We discuss a patient who developed an "alien limb" on her right side after brain herniation. She reported feeling as though her arm movements were controlled by a stranger and displayed limb levitation and groping behaviors. She received 0.5 mg clonazepam b.i.d. This was followed by a limb levitation frequency reduction of 73%. Discontinuation and retrial of clonazepam verified this response. She suffered a psychotic episode that she attributed to clonazepam. Clonazepam was discontinued. She received botulinum toxin injections to her arm that reduced her limb levitation by 84%. This is the first report of response to medication in alien limb syndrome.