Objective: To document acute angle closure glaucoma temporally related to ingestion of oral imipramine hydrochloride. Patients: Four patients with narrow angles received routinely prescribed doses of imipramine that triggered acute angle closure glaucoma. Outcome: Laser iridotomy was successful in all patients. Conclusions: Psychoactive drugs should be prescribed cautiously in patients with known narrow angles and should be monitored by an ophthalmologist.