diff --git a/src/cli/commands/scan.ts b/src/cli/commands/scan.ts
index eb261ce..55ce6bf 100644
--- a/src/cli/commands/scan.ts
+++ b/src/cli/commands/scan.ts
@@ -6,6 +6,7 @@ import { reportTerminal } from '../../reporters/terminal.js';
 import { reportJson } from '../../reporters/json.js';
 import { reportHtml } from '../../reporters/html.js';
 import { reportSarif } from '../../reporters/sarif.js';
+import { reportJunit } from '../../reporters/junit.js';
 import { reportComplianceHtml, SUPPORTED_STANDARDS } from '../../reporters/compliance-html.js';
 import { loadConfig } from '../../config/loader.js';
 import { createSpinner } from '../ui.js';
@@ -19,6 +20,7 @@ export const scanCommand = new Command('scan')
   .option('--json', 'Output as JSON')
   .option('--html [file]', 'Output as HTML report')
   .option('--sarif [file]', 'Output as SARIF 2.1.0')
+  .option('--junit [file]', 'Output as JUnit XML for CI integration')
   .option('-o, --output <file>', 'Write JSON output to file')
   .option('-q, --quiet', 'Suppress terminal output')
   .option('--severity <level>', 'Minimum severity to report (critical|high|medium|low)')
@@ -47,6 +49,7 @@ export const scanCommand = new Command('scan')
     json?: boolean;
     html?: string | boolean;
     sarif?: string | boolean;
+    junit?: string | boolean;
     output?: string;
     quiet?: boolean;
     severity?: string;
@@ -211,7 +214,15 @@ export const scanCommand = new Command('scan')
       result.findings = allFindings.filter(f => (confidenceOrder[f.confidence] ?? 2) <= minLevel);
       const hiddenLowConfidence = allFindings.length - result.findings.length;
 
-      if (options.sarif) {
+      if (options.junit) {
+        const junitPath = typeof options.junit === 'string' ? options.junit : undefined;
+        const junit = reportJunit(result, junitPath);
+        if (!junitPath) {
+          console.log(junit);
+        } else if (!options.quiet) {
+          console.log(`JUnit XML report written to: ${junitPath}`);
+        }
+      } else if (options.sarif) {
         const sarifPath = typeof options.sarif === 'string'
           ? options.sarif
           : undefined;
diff --git a/src/reporters/junit.ts b/src/reporters/junit.ts
new file mode 100644
index 0000000..7914ccf
--- /dev/null
+++ b/src/reporters/junit.ts
@@ -0,0 +1,69 @@
+import * as fs from 'node:fs';
+import type { ScanResult } from '../types/score.js';
+import type { Finding } from '../types/finding.js';
+
+function escapeXml(str: string): string {
+  return str
+    .replace(/&/g, '&amp;')
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;')
+    .replace(/"/g, '&quot;')
+    .replace(/'/g, '&apos;');
+}
+
+export function reportJunit(result: ScanResult, outputPath?: string): string {
+  // Group findings by domain
+  const byDomain = new Map<string, Finding[]>();
+  for (const finding of result.findings) {
+    const domain = finding.domain;
+    if (!byDomain.has(domain)) {
+      byDomain.set(domain, []);
+    }
+    byDomain.get(domain)!.push(finding);
+  }
+
+  const totalTests = result.findings.length;
+  const totalFailures = result.findings.filter(
+    f => f.severity === 'critical' || f.severity === 'high' || f.severity === 'medium',
+  ).length;
+
+  const lines: string[] = [
+    '<?xml version="1.0" encoding="UTF-8"?>',
+    `<testsuites name="g0-scan" tests="${totalTests}" failures="${totalFailures}">`,
+  ];
+
+  for (const [domain, findings] of byDomain) {
+    const suiteFailures = findings.filter(
+      f => f.severity === 'critical' || f.severity === 'high' || f.severity === 'medium',
+    ).length;
+
+    lines.push(`  <testsuite name="${escapeXml(domain)}" tests="${findings.length}" failures="${suiteFailures}">`);
+
+    for (const finding of findings) {
+      const isFail = finding.severity === 'critical' || finding.severity === 'high' || finding.severity === 'medium';
+      lines.push(`    <testcase name="${escapeXml(finding.ruleId)}" classname="${escapeXml(domain)}">`);
+
+      if (isFail) {
+        const message = escapeXml(finding.title);
+        const body = `File: ${finding.location.file}:${finding.location.line}\nRule: ${finding.ruleId} - ${finding.title}${finding.remediation ? `\nRemediation: ${finding.remediation}` : ''}`;
+        lines.push(`      <failure message="${message}" type="${escapeXml(finding.severity)}">`);
+        lines.push(`        ${escapeXml(body)}`);
+        lines.push('      </failure>');
+      }
+
+      lines.push('    </testcase>');
+    }
+
+    lines.push('  </testsuite>');
+  }
+
+  lines.push('</testsuites>');
+
+  const xml = lines.join('\n');
+
+  if (outputPath) {
+    fs.writeFileSync(outputPath, xml, 'utf-8');
+  }
+
+  return xml;
+}
diff --git a/tests/unit/junit-reporter.test.ts b/tests/unit/junit-reporter.test.ts
new file mode 100644
index 0000000..fc934ec
--- /dev/null
+++ b/tests/unit/junit-reporter.test.ts
@@ -0,0 +1,143 @@
+import { describe, it, expect } from 'vitest';
+import { reportJunit } from '../../src/reporters/junit.js';
+import type { ScanResult } from '../../src/types/score.js';
+import type { Finding } from '../../src/types/finding.js';
+
+function makeFinding(overrides?: Partial<Finding>): Finding {
+  return {
+    id: 'AA-GI-001-0',
+    ruleId: 'AA-GI-001',
+    title: 'Test finding',
+    description: 'Test description',
+    severity: 'high',
+    confidence: 'high',
+    domain: 'goal-integrity',
+    location: { file: 'agent.py', line: 10, snippet: 'some code here' },
+    remediation: 'Fix it',
+    standards: { owaspAgentic: ['ASI01'] },
+    ...overrides,
+  };
+}
+
+function makeScanResult(findings: Finding[]): ScanResult {
+  return {
+    findings,
+    score: {
+      overall: 75,
+      grade: 'C' as const,
+      domains: [],
+    },
+    graph: {
+      rootPath: '/test',
+      primaryFramework: 'langchain',
+      secondaryFrameworks: [],
+      agents: [],
+      tools: [],
+      prompts: [],
+      files: { all: [], python: [], typescript: [], javascript: [], configs: [] },
+      models: [],
+      vectorDBs: [],
+      mcpServers: [],
+    },
+    timestamp: '2025-01-01T00:00:00.000Z',
+    duration: 1000,
+  };
+}
+
+describe('JUnit XML Reporter', () => {
+  it('generates valid JUnit XML structure', () => {
+    const result = makeScanResult([makeFinding()]);
+    const xml = reportJunit(result);
+
+    expect(xml).toContain('<?xml version="1.0" encoding="UTF-8"?>');
+    expect(xml).toContain('<testsuites name="g0-scan"');
+    expect(xml).toContain('tests="1"');
+    expect(xml).toContain('failures="1"');
+    expect(xml).toContain('<testsuite name="goal-integrity"');
+    expect(xml).toContain('<testcase name="AA-GI-001"');
+    expect(xml).toContain('classname="goal-integrity"');
+  });
+
+  it('marks high/critical/medium as failures, low/info as pass', () => {
+    const result = makeScanResult([
+      makeFinding({ id: 'f1', ruleId: 'R-001', severity: 'critical', domain: 'tool-safety' }),
+      makeFinding({ id: 'f2', ruleId: 'R-002', severity: 'high', domain: 'tool-safety' }),
+      makeFinding({ id: 'f3', ruleId: 'R-003', severity: 'medium', domain: 'tool-safety' }),
+      makeFinding({ id: 'f4', ruleId: 'R-004', severity: 'low', domain: 'tool-safety' }),
+      makeFinding({ id: 'f5', ruleId: 'R-005', severity: 'info', domain: 'tool-safety' }),
+    ]);
+    const xml = reportJunit(result);
+
+    expect(xml).toContain('tests="5" failures="3"');
+    // critical, high, medium have <failure>
+    expect((xml.match(/<failure /g) || []).length).toBe(3);
+  });
+
+  it('groups findings by domain into testsuites', () => {
+    const result = makeScanResult([
+      makeFinding({ id: 'f1', ruleId: 'R-001', domain: 'tool-safety' }),
+      makeFinding({ id: 'f2', ruleId: 'R-002', domain: 'goal-integrity' }),
+      makeFinding({ id: 'f3', ruleId: 'R-003', domain: 'tool-safety' }),
+    ]);
+    const xml = reportJunit(result);
+
+    expect((xml.match(/<testsuite /g) || []).length).toBe(2);
+    expect(xml).toContain('<testsuite name="tool-safety" tests="2"');
+    expect(xml).toContain('<testsuite name="goal-integrity" tests="1"');
+  });
+
+  it('escapes XML special characters', () => {
+    const result = makeScanResult([
+      makeFinding({ title: 'Finding with <special> & "chars"' }),
+    ]);
+    const xml = reportJunit(result);
+
+    expect(xml).toContain('&lt;special&gt;');
+    expect(xml).toContain('&amp;');
+    expect(xml).toContain('&quot;chars&quot;');
+    // Must be valid XML (no unescaped < > & in content)
+    expect(xml).not.toMatch(/<failure[^>]*>[^<]*<[^/!][^<]*<\/failure>/);
+  });
+
+  it('handles empty findings', () => {
+    const result = makeScanResult([]);
+    const xml = reportJunit(result);
+
+    expect(xml).toContain('tests="0" failures="0"');
+    expect(xml).not.toContain('<testsuite ');
+  });
+
+  it('includes file location and remediation in failure body', () => {
+    const result = makeScanResult([
+      makeFinding({
+        ruleId: 'AA-TS-003',
+        title: 'Unsandboxed tool call',
+        location: { file: 'tools.ts', line: 18 },
+        remediation: 'Add sandbox wrapper',
+      }),
+    ]);
+    const xml = reportJunit(result);
+
+    expect(xml).toContain('tools.ts:18');
+    expect(xml).toContain('AA-TS-003');
+    expect(xml).toContain('Add sandbox wrapper');
+  });
+
+  it('writes to file when outputPath is provided', async () => {
+    const fs = await import('node:fs');
+    const os = await import('node:os');
+    const path = await import('node:path');
+    const tmpFile = path.join(os.tmpdir(), `junit-test-${Date.now()}.xml`);
+
+    try {
+      const result = makeScanResult([makeFinding()]);
+      reportJunit(result, tmpFile);
+
+      const content = fs.readFileSync(tmpFile, 'utf-8');
+      expect(content).toContain('<?xml version="1.0"');
+      expect(content).toContain('<testsuites');
+    } finally {
+      fs.unlinkSync(tmpFile);
+    }
+  });
+});