diff --git a/src/main/services/worktree.service.ts b/src/main/services/worktree.service.ts
index 27c9c68..db76c02 100644
--- a/src/main/services/worktree.service.ts
+++ b/src/main/services/worktree.service.ts
@@ -1,6 +1,6 @@
 import simpleGit from 'simple-git'
-import { join, dirname, basename } from 'path'
-import { mkdir, access } from 'fs/promises'
+import { join, dirname, basename, resolve as resolvePath } from 'path'
+import { mkdir, access, realpath } from 'fs/promises'
 import type { WorktreeInfo } from '../../shared/types'
 
 function worktreeDir(repoPath: string): string {
@@ -8,6 +8,19 @@ function worktreeDir(repoPath: string): string {
   return join(dirname(repoPath), '.codecrucible-worktrees', repoName)
 }
 
+// `git worktree prune` clears stale administrative entries left behind when a
+// worktree's directory is deleted or moved outside of git (e.g. after the
+// parent repo itself is moved). Stale entries keep their branch "in use",
+// which causes tools like GitHub Desktop to fail with
+// `cannot delete branch '...' used by worktree at '...'`.
+async function pruneWorktrees(repoPath: string): Promise<void> {
+  try {
+    await simpleGit(repoPath).raw(['worktree', 'prune'])
+  } catch {
+    // Best-effort cleanup
+  }
+}
+
 // If `branch` is currently checked out in some worktree, detach that worktree
 // (HEAD becomes detached at the same commit) so we can add a new worktree
 // claiming the branch. Returns the path that was detached, or null.
@@ -49,6 +62,7 @@ export async function createWorktree(
   const wtPath = join(wtBase, sessionName)
 
   await mkdir(wtBase, { recursive: true })
+  await pruneWorktrees(repoPath)
 
   // Check if repo has any commits
   let hasCommits = true
@@ -104,6 +118,7 @@ export async function createWorktreeFromBranch(
   const wtPath = join(wtBase, sessionName)
 
   await mkdir(wtBase, { recursive: true })
+  await pruneWorktrees(repoPath)
 
   // Fetch the branch from origin
   await g.raw(['fetch', 'origin', remoteBranch])
@@ -146,6 +161,7 @@ export async function createWorktreeFromBranch(
 
 export async function listWorktrees(repoPath: string): Promise<WorktreeInfo[]> {
   const g = simpleGit(repoPath)
+  await pruneWorktrees(repoPath)
   const result = await g.raw(['worktree', 'list', '--porcelain'])
 
   const worktrees: WorktreeInfo[] = []
@@ -169,5 +185,84 @@ export async function listWorktrees(repoPath: string): Promise<WorktreeInfo[]> {
 
 export async function removeWorktree(repoPath: string, worktreePath: string): Promise<void> {
   const g = simpleGit(repoPath)
-  await g.raw(['worktree', 'remove', worktreePath, '--force'])
+
+  // Look up the branch attached to this worktree before we remove it, so we
+  // can delete an orphaned `session/*` branch and avoid leaving dangling refs
+  // that block branch deletion in other tools (e.g. GitHub Desktop).
+  // Normalize both sides via realpath so symlinked paths (e.g. macOS /var vs
+  // /private/var) and trailing-slash differences don't cause a miss.
+  const normalize = async (p: string): Promise<string> => {
+    try {
+      return await realpath(p)
+    } catch {
+      // The path may not exist (e.g. the worktree directory was already
+      // deleted). Resolve the parent — usually still present — and re-append
+      // the basename so symlinked ancestors (e.g. macOS /var → /private/var)
+      // are still followed.
+      try {
+        const parent = await realpath(dirname(p))
+        return join(parent, basename(p))
+      } catch {
+        return resolvePath(p)
+      }
+    }
+  }
+  const targetPath = await normalize(worktreePath)
+  let attachedBranch: string | null = null
+  try {
+    const wtOutput = await g.raw(['worktree', 'list', '--porcelain'])
+    let currentPath = ''
+    for (const line of wtOutput.split('\n')) {
+      if (line.startsWith('worktree ')) {
+        currentPath = await normalize(line.slice('worktree '.length))
+      } else if (line.startsWith('branch refs/heads/') && currentPath === targetPath) {
+        attachedBranch = line.slice('branch refs/heads/'.length)
+        break
+      }
+    }
+  } catch {
+    // Best-effort lookup
+  }
+
+  let removeError: unknown = null
+  try {
+    await g.raw(['worktree', 'remove', worktreePath, '--force'])
+  } catch (err) {
+    removeError = err
+  }
+  await pruneWorktrees(repoPath)
+
+  let removed = removeError === null
+  if (removeError) {
+    // The remove may have failed simply because the directory was already gone
+    // and git's admin entry was stale. After prune, re-check the worktree list:
+    // if our target is no longer registered, treat the removal as successful;
+    // otherwise surface the original error.
+    let stillPresent = true
+    try {
+      const wtOutput = await g.raw(['worktree', 'list', '--porcelain'])
+      stillPresent = false
+      for (const line of wtOutput.split('\n')) {
+        if (line.startsWith('worktree ')) {
+          const p = await normalize(line.slice('worktree '.length))
+          if (p === targetPath) {
+            stillPresent = true
+            break
+          }
+        }
+      }
+    } catch {
+      // If we can't list, treat the worktree as still present and rethrow.
+    }
+    if (stillPresent) throw removeError
+    removed = true
+  }
+
+  if (removed && attachedBranch && attachedBranch.startsWith('session/')) {
+    try {
+      await g.raw(['branch', '-D', attachedBranch])
+    } catch {
+      // Branch may not exist or may be checked out elsewhere
+    }
+  }
 }
diff --git a/tests/unit/main/worktree.service.test.ts b/tests/unit/main/worktree.service.test.ts
new file mode 100644
index 0000000..acb03f8
--- /dev/null
+++ b/tests/unit/main/worktree.service.test.ts
@@ -0,0 +1,105 @@
+import { afterEach, beforeEach, describe, expect, it } from 'vitest'
+import { mkdir, mkdtemp, realpath, rm, writeFile } from 'fs/promises'
+import { tmpdir } from 'os'
+import { join } from 'path'
+import simpleGit from 'simple-git'
+import {
+  createWorktree,
+  listWorktrees,
+  removeWorktree,
+} from '../../../src/main/services/worktree.service'
+
+let tmpRoot: string
+let repoPath: string
+
+async function initRepo(path: string) {
+  const g = simpleGit(path)
+  await g.init()
+  await g.addConfig('user.email', 'test@example.com')
+  await g.addConfig('user.name', 'Test')
+  await g.addConfig('commit.gpgsign', 'false')
+  // Some hosts default init.defaultBranch elsewhere; force `main` so tests are
+  // deterministic regardless of the user's git config.
+  await g.raw(['symbolic-ref', 'HEAD', 'refs/heads/main'])
+  await writeFile(join(path, 'README.md'), 'hello\n')
+  await g.add('README.md')
+  await g.commit('initial')
+}
+
+beforeEach(async () => {
+  tmpRoot = await mkdtemp(join(tmpdir(), 'cc-wt-test-'))
+  repoPath = join(tmpRoot, 'repo')
+  await mkdir(repoPath, { recursive: true })
+  await initRepo(repoPath)
+})
+
+afterEach(async () => {
+  await rm(tmpRoot, { recursive: true, force: true })
+})
+
+describe('worktree.service', () => {
+  it('createWorktree creates a session/<name> branch and worktree dir', async () => {
+    const info = await createWorktree(repoPath, 'feat/x', 'main')
+    expect(info.branch).toBe('session/feat/x')
+    expect(info.path.endsWith('feat/x')).toBe(true)
+
+    const list = await listWorktrees(repoPath)
+    const found = list.find((w) => w.branch === 'session/feat/x')
+    expect(found).toBeDefined()
+    // macOS resolves /var to /private/var, so compare via realpath.
+    expect(await realpath(found!.path)).toBe(await realpath(info.path))
+  })
+
+  it('removeWorktree removes the worktree and deletes its session/* branch', async () => {
+    const info = await createWorktree(repoPath, 'feat/y', 'main')
+    await removeWorktree(repoPath, info.path)
+
+    const list = await listWorktrees(repoPath)
+    expect(list.find((w) => w.branch === 'session/feat/y')).toBeUndefined()
+
+    const branches = await simpleGit(repoPath).branch()
+    expect(Object.keys(branches.branches)).not.toContain('session/feat/y')
+  })
+
+  it('listWorktrees prunes stale entries from a deleted worktree directory', async () => {
+    const info = await createWorktree(repoPath, 'feat/stale', 'main')
+
+    // Simulate the user deleting the worktree dir outside of git (or moving
+    // the parent repo) — git keeps a stale admin entry under .git/worktrees/
+    // that keeps the branch "in use" until pruned.
+    await rm(info.path, { recursive: true, force: true })
+
+    const list = await listWorktrees(repoPath)
+    // After prune, the stale entry is gone from `worktree list`.
+    expect(list.find((w) => w.path === info.path)).toBeUndefined()
+
+    // And the branch can now be deleted by other tools (e.g. GitHub Desktop)
+    // because the worktree no longer claims it.
+    await expect(
+      simpleGit(repoPath).raw(['branch', '-D', 'session/feat/stale'])
+    ).resolves.toBeDefined()
+  })
+
+  it('removeWorktree succeeds even when the worktree directory is already gone', async () => {
+    const info = await createWorktree(repoPath, 'feat/gone', 'main')
+    await rm(info.path, { recursive: true, force: true })
+
+    await expect(removeWorktree(repoPath, info.path)).resolves.toBeUndefined()
+
+    const branches = await simpleGit(repoPath).branch()
+    expect(Object.keys(branches.branches)).not.toContain('session/feat/gone')
+  })
+
+  it('removeWorktree leaves non-session branches alone', async () => {
+    // Create a regular branch and attach a worktree to it manually.
+    const g = simpleGit(repoPath)
+    await g.raw(['branch', 'keepme', 'main'])
+    const wtPath = join(tmpRoot, 'extwt')
+    await g.raw(['worktree', 'add', wtPath, 'keepme'])
+
+    await removeWorktree(repoPath, wtPath)
+
+    const branches = await g.branch()
+    expect(Object.keys(branches.branches)).toContain('keepme')
+  })
+})