diff --git a/lib/pdf/incident-report.ts b/lib/pdf/incident-report.ts
new file mode 100644
index 0000000..f48ce12
--- /dev/null
+++ b/lib/pdf/incident-report.ts
@@ -0,0 +1,263 @@
+import { PDFDocument, StandardFonts, rgb } from 'pdf-lib'
+
+export type IncidentReportData = {
+  referenceNo: string | null
+  incidentType: string
+  reportedAt: string
+  siteName: string
+  zoneName: string | null
+  reporterName: string
+  severity: number | null
+  medicalStatus: string | null
+  description: string
+  injuryInvolved: boolean
+  assetInvolved: boolean
+  isFatality: boolean
+  isSeriousBodilyInjury: boolean
+  isDangerousOccurrence: boolean
+  isOccupationalDisease: boolean
+  lostDays: number | null
+  triagedBy: string | null
+  triagedAt: string | null
+  triageNotes: string | null
+  investigation: {
+    method: string
+    findingsText: string | null
+    rootCauseSummary: string | null
+    alcoholTestResult: string | null
+    urineTestResult: string | null
+  } | null
+  capas: Array<{
+    description: string
+    ownerName: string
+    department: string
+    dueDate: string
+    priority: string
+    status: string
+    completedAt: string | null
+    ownerNotes: string | null
+  }>
+  addenda: Array<{
+    authorName: string
+    createdAt: string
+    body: string
+  }>
+  closedAt: string | null
+}
+
+type EmbeddedFont = Awaited<ReturnType<PDFDocument['embedFont']>>
+type Page = ReturnType<PDFDocument['addPage']>
+
+const MARGIN = 50
+const PAGE_WIDTH = 595
+const PAGE_HEIGHT = 842
+const BODY_FONT_SIZE = 10
+const LABEL_FONT_SIZE = 9
+const SECTION_FONT_SIZE = 11
+const LINE_HEIGHT = 16
+const SECTION_GAP = 20
+const BOTTOM_MARGIN = 60
+
+type State = {
+  doc: PDFDocument
+  pages: Page[]
+  font: EmbeddedFont
+  boldFont: EmbeddedFont
+  y: number
+}
+
+function currentPage(state: State): Page {
+  return state.pages[state.pages.length - 1]
+}
+
+function newPage(state: State): void {
+  const page = state.doc.addPage([PAGE_WIDTH, PAGE_HEIGHT])
+  state.pages.push(page)
+  state.y = PAGE_HEIGHT - MARGIN
+}
+
+function ensureSpace(state: State, needed: number): void {
+  if (state.y - needed < BOTTOM_MARGIN) newPage(state)
+}
+
+function wrapText(text: string, maxWidth: number, font: EmbeddedFont, size: number): string[] {
+  const words = text.split(' ')
+  const lines: string[] = []
+  let current = ''
+  for (const word of words) {
+    const test = current ? `${current} ${word}` : word
+    if (font.widthOfTextAtSize(test, size) > maxWidth && current) {
+      lines.push(current)
+      current = word
+    } else {
+      current = test
+    }
+  }
+  if (current) lines.push(current)
+  return lines.length ? lines : ['']
+}
+
+function drawSection(state: State, title: string): void {
+  ensureSpace(state, SECTION_GAP + LINE_HEIGHT + 6)
+  state.y -= SECTION_GAP
+  currentPage(state).drawRectangle({
+    x: MARGIN, y: state.y - 4,
+    width: PAGE_WIDTH - MARGIN * 2, height: LINE_HEIGHT + 4,
+    color: rgb(0.9, 0.95, 0.9),
+  })
+  currentPage(state).drawText(title.toUpperCase(), {
+    x: MARGIN + 4, y: state.y,
+    size: SECTION_FONT_SIZE, font: state.boldFont, color: rgb(0.05, 0.4, 0.1),
+  })
+  state.y -= LINE_HEIGHT + 8
+}
+
+function drawField(state: State, label: string, value: string | null): void {
+  const v = value ?? '—'
+  const maxW = PAGE_WIDTH - MARGIN * 2 - 120
+  const lines = wrapText(v, maxW, state.font, BODY_FONT_SIZE)
+  ensureSpace(state, (lines.length + 1) * LINE_HEIGHT)
+  currentPage(state).drawText(label + ':', {
+    x: MARGIN, y: state.y,
+    size: LABEL_FONT_SIZE, font: state.boldFont, color: rgb(0.3, 0.3, 0.3),
+  })
+  for (const line of lines) {
+    currentPage(state).drawText(line, {
+      x: MARGIN + 120, y: state.y,
+      size: BODY_FONT_SIZE, font: state.font, color: rgb(0, 0, 0),
+    })
+    state.y -= LINE_HEIGHT
+  }
+  if (lines.length === 0) state.y -= LINE_HEIGHT
+}
+
+function fmt(iso: string | null): string {
+  if (!iso) return '—'
+  return new Date(iso).toLocaleString('en-MY', { timeZone: 'Asia/Kuala_Lumpur', hour12: false })
+}
+
+function fmtDate(iso: string | null): string {
+  if (!iso) return '—'
+  return new Date(iso).toLocaleDateString('en-MY', { timeZone: 'Asia/Kuala_Lumpur' })
+}
+
+export async function buildIncidentReportPdf(data: IncidentReportData): Promise<Uint8Array> {
+  const doc = await PDFDocument.create()
+  const font = await doc.embedFont(StandardFonts.Helvetica)
+  const boldFont = await doc.embedFont(StandardFonts.HelveticaBold)
+
+  const firstPage = doc.addPage([PAGE_WIDTH, PAGE_HEIGHT])
+  const state: State = { doc, pages: [firstPage], font, boldFont, y: PAGE_HEIGHT - MARGIN }
+
+  // ── Header ──────────────────────────────────────────────────────────────
+  currentPage(state).drawText('INCIDENT INVESTIGATION REPORT', {
+    x: MARGIN, y: state.y,
+    size: 16, font: boldFont, color: rgb(0.05, 0.4, 0.1),
+  })
+  state.y -= 22
+  currentPage(state).drawText(`Reference: ${data.referenceNo ?? '—'}`, {
+    x: MARGIN, y: state.y,
+    size: 10, font, color: rgb(0.2, 0.2, 0.2),
+  })
+  currentPage(state).drawText(`Generated: ${fmt(new Date().toISOString())}`, {
+    x: PAGE_WIDTH - MARGIN - 160, y: state.y,
+    size: 10, font, color: rgb(0.2, 0.2, 0.2),
+  })
+  state.y -= 6
+  currentPage(state).drawLine({
+    start: { x: MARGIN, y: state.y },
+    end: { x: PAGE_WIDTH - MARGIN, y: state.y },
+    thickness: 1.5, color: rgb(0.05, 0.4, 0.1),
+  })
+  state.y -= 12
+
+  // ── Incident Details ─────────────────────────────────────────────────────
+  drawSection(state, 'Incident Details')
+  drawField(state, 'Type', data.incidentType.replace(/_/g, ' '))
+  drawField(state, 'Reported At', fmt(data.reportedAt))
+  drawField(state, 'Site', data.siteName)
+  drawField(state, 'Zone', data.zoneName)
+  drawField(state, 'Reported By', data.reporterName)
+  drawField(state, 'Severity', data.severity !== null ? String(data.severity) + ' / 5' : null)
+  drawField(state, 'Medical Status', data.medicalStatus?.replace(/_/g, ' ') ?? null)
+  drawField(state, 'Injury Involved', data.injuryInvolved ? 'Yes' : 'No')
+  drawField(state, 'Asset Involved', data.assetInvolved ? 'Yes' : 'No')
+  drawField(state, 'Fatality', data.isFatality ? 'Yes' : 'No')
+  drawField(state, 'Serious Bodily Injury', data.isSeriousBodilyInjury ? 'Yes' : 'No')
+  drawField(state, 'Dangerous Occurrence', data.isDangerousOccurrence ? 'Yes' : 'No')
+  drawField(state, 'Occupational Disease', data.isOccupationalDisease ? 'Yes' : 'No')
+  drawField(state, 'Lost Days', data.lostDays !== null ? String(data.lostDays) : null)
+  drawField(state, 'Description', data.description)
+
+  // ── Triage ───────────────────────────────────────────────────────────────
+  if (data.triagedBy) {
+    drawSection(state, 'Triage')
+    drawField(state, 'Triaged By', data.triagedBy)
+    drawField(state, 'Triaged At', fmt(data.triagedAt))
+    drawField(state, 'Triage Notes', data.triageNotes)
+  }
+
+  // ── Investigation ────────────────────────────────────────────────────────
+  if (data.investigation) {
+    const inv = data.investigation
+    drawSection(state, 'Investigation')
+    drawField(state, 'Method', inv.method.replace(/_/g, ' '))
+    drawField(state, 'Findings', inv.findingsText)
+    drawField(state, 'Root Cause', inv.rootCauseSummary)
+    drawField(state, 'Alcohol Test', inv.alcoholTestResult)
+    drawField(state, 'Urine Test', inv.urineTestResult)
+  }
+
+  // ── CAPA Actions ─────────────────────────────────────────────────────────
+  if (data.capas.length > 0) {
+    drawSection(state, `CAPA Actions (${data.capas.length})`)
+    for (let i = 0; i < data.capas.length; i++) {
+      const c = data.capas[i]
+      ensureSpace(state, LINE_HEIGHT)
+      currentPage(state).drawText(`#${i + 1}`, {
+        x: MARGIN, y: state.y,
+        size: BODY_FONT_SIZE, font: boldFont, color: rgb(0, 0, 0),
+      })
+      state.y -= LINE_HEIGHT
+      drawField(state, 'Action', c.description)
+      drawField(state, 'Owner', c.ownerName)
+      drawField(state, 'Department', c.department)
+      drawField(state, 'Due Date', fmtDate(c.dueDate))
+      drawField(state, 'Priority', c.priority.toUpperCase())
+      drawField(state, 'Status', c.status.replace(/_/g, ' '))
+      if (c.completedAt) drawField(state, 'Completed At', fmt(c.completedAt))
+      if (c.ownerNotes) drawField(state, 'Owner Notes', c.ownerNotes)
+      state.y -= 8
+    }
+  }
+
+  // ── Addenda ──────────────────────────────────────────────────────────────
+  if (data.addenda.length > 0) {
+    drawSection(state, `Addenda (${data.addenda.length})`)
+    for (const a of data.addenda) {
+      drawField(state, 'Author', a.authorName)
+      drawField(state, 'Date', fmt(a.createdAt))
+      drawField(state, 'Note', a.body)
+      state.y -= 8
+    }
+  }
+
+  // ── Closure ──────────────────────────────────────────────────────────────
+  drawSection(state, 'Closure')
+  drawField(state, 'Closed At', fmt(data.closedAt))
+
+  // ── Footer on all pages ──────────────────────────────────────────────────
+  for (const page of state.pages) {
+    page.drawText('Generated by IMS — Confidential', {
+      x: MARGIN, y: 30,
+      size: 8, font, color: rgb(0.5, 0.5, 0.5),
+    })
+    page.drawLine({
+      start: { x: MARGIN, y: 42 },
+      end: { x: PAGE_WIDTH - MARGIN, y: 42 },
+      thickness: 0.5, color: rgb(0.8, 0.8, 0.8),
+    })
+  }
+
+  return doc.save()
+}
diff --git a/tests/lib/pdf/incident-report.test.ts b/tests/lib/pdf/incident-report.test.ts
new file mode 100644
index 0000000..b47e0f5
--- /dev/null
+++ b/tests/lib/pdf/incident-report.test.ts
@@ -0,0 +1,77 @@
+import { describe, it, expect } from 'vitest'
+import { buildIncidentReportPdf, type IncidentReportData } from '@/lib/pdf/incident-report'
+
+const MOCK: IncidentReportData = {
+  referenceNo: 'SC1-202607-0001',
+  incidentType: 'injury',
+  reportedAt: '2026-07-01T08:00:00.000Z',
+  siteName: 'Setia Warehouse KL',
+  zoneName: 'Loading Bay A',
+  reporterName: 'Ahmad Bin Ali',
+  severity: 3,
+  medicalStatus: 'first_aid',
+  description: 'Worker slipped on wet floor near loading bay.',
+  injuryInvolved: true,
+  assetInvolved: false,
+  isFatality: false,
+  isSeriousBodilyInjury: false,
+  isDangerousOccurrence: false,
+  isOccupationalDisease: false,
+  lostDays: null,
+  triagedBy: 'Supervisor Tan',
+  triagedAt: '2026-07-01T10:00:00.000Z',
+  triageNotes: 'Reviewed on-site. First aid applied.',
+  investigation: {
+    method: 'five_why',
+    findingsText: 'Floor was wet due to a leaking pipe.',
+    rootCauseSummary: 'Maintenance backlog on pipe inspection.',
+    alcoholTestResult: 'negative',
+    urineTestResult: 'negative',
+  },
+  capas: [
+    {
+      description: 'Install non-slip mats in loading bay.',
+      ownerName: 'Maintenance Dept',
+      department: 'Maintenance',
+      dueDate: '2026-07-15',
+      priority: 'high',
+      status: 'closed',
+      completedAt: '2026-07-14T09:00:00.000Z',
+      ownerNotes: 'Mats installed and inspected.',
+    },
+  ],
+  addenda: [
+    {
+      authorName: 'HSE Officer Lim',
+      createdAt: '2026-07-20T14:00:00.000Z',
+      body: 'Follow-up inspection passed. Area cleared.',
+    },
+  ],
+  closedAt: '2026-07-20T15:00:00.000Z',
+}
+
+describe('buildIncidentReportPdf', () => {
+  it('returns a Uint8Array starting with PDF magic bytes', async () => {
+    const result = await buildIncidentReportPdf(MOCK)
+    expect(result).toBeInstanceOf(Uint8Array)
+    // PDF files start with %PDF
+    const header = String.fromCharCode(...result.slice(0, 4))
+    expect(header).toBe('%PDF')
+  })
+
+  it('handles incident with no investigation, CAPAs, or addenda', async () => {
+    const minimal: IncidentReportData = {
+      ...MOCK,
+      triagedBy: null,
+      triagedAt: null,
+      triageNotes: null,
+      investigation: null,
+      capas: [],
+      addenda: [],
+    }
+    const result = await buildIncidentReportPdf(minimal)
+    expect(result).toBeInstanceOf(Uint8Array)
+    const header = String.fromCharCode(...result.slice(0, 4))
+    expect(header).toBe('%PDF')
+  })
+})