diff --git a/src/git/diff.ts b/src/git/diff.ts
index 64a2cc0..fc38e0f 100644
--- a/src/git/diff.ts
+++ b/src/git/diff.ts
@@ -55,14 +55,43 @@ export function getStagedDiff(): DiffResult {
   };
 }
 
+function getUntrackedDiff(): string {
+  const files = spawnSync('git', ['ls-files', '--others', '--exclude-standard', '-z'], {
+    encoding: 'utf-8',
+    maxBuffer: GIT_DIFF_MAX_BUFFER,
+  });
+  if (files.error) throw files.error;
+  if (files.status !== 0) {
+    throw new Error(files.stderr.trim() || `git ls-files exited with code ${files.status}`);
+  }
+
+  return files.stdout
+    .split('\0')
+    .filter(Boolean)
+    .map((file) => {
+      const result = spawnSync('git', ['diff', '--no-index', '--', '/dev/null', file], {
+        encoding: 'utf-8',
+        maxBuffer: GIT_DIFF_MAX_BUFFER,
+      });
+      if (result.error) throw result.error;
+      if (result.status !== 0 && result.status !== 1) {
+        throw new Error(result.stderr.trim() || `git diff --no-index exited with code ${result.status}`);
+      }
+      return result.stdout;
+    })
+    .filter(Boolean)
+    .join('\n');
+}
+
 export function getUnstagedDiff(): DiffResult {
-  const diff = execSync('git diff', {
+  const trackedDiff = execSync('git diff', {
     encoding: 'utf-8',
     maxBuffer: GIT_DIFF_MAX_BUFFER,
   });
+  const diff = [trackedDiff, getUntrackedDiff()].filter(Boolean).join('\n').trim();
   return {
-    diff: diff.trim(),
-    hasChanges: diff.trim().length > 0,
+    diff,
+    hasChanges: diff.length > 0,
     staged: false,
   };
 }
diff --git a/tests/git-diff.test.mjs b/tests/git-diff.test.mjs
index fba896f..579916d 100644
--- a/tests/git-diff.test.mjs
+++ b/tests/git-diff.test.mjs
@@ -190,6 +190,26 @@ test("getUnstagedDiff returns diff for unstaged changes", () => {
   }
 });
 
+test("getUnstagedDiff includes untracked files", () => {
+  const repoDir = initRepo();
+
+  try {
+    git(["commit", "--allow-empty", "-m", "initial commit"], repoDir);
+    writeFileSync(join(repoDir, "new-file.txt"), "untracked content\n", "utf-8");
+
+    withCwd(repoDir, () => {
+      const result = getUnstagedDiff();
+
+      assert.equal(result.hasChanges, true);
+      assert.equal(result.staged, false);
+      assert.ok(result.diff.includes("new-file.txt"));
+      assert.ok(result.diff.includes("+untracked content"));
+    });
+  } finally {
+    rmSync(repoDir, { recursive: true, force: true });
+  }
+});
+
 test("getUnstagedDiff handles diffs larger than the default execSync buffer", () => {
   const repoDir = initRepo();