Adult respiratory distress syndrome (ARDS) from overdose of tricyclic antidepressants (TCA) has been rarely reported in the literature. We describe a case report of ARDS secondary to amitriptyline overdose. A 39-y-old comatose female was admitted to the emergency department after ingesting approximately 2 g of amitriptyline 1-12 h prior to arrival. Patient was intubated and physostigmine was administered. There was only minimal level of improvement in the patient's consciousness. Gastric lavage was followed by charcoal and magnesium citrate; no material was recovered from the stomach. The patient was transferred to the intensive care unit and placed on a ventilator. Chest radiographic study on day 2 of hospital admission revealed bilateral diffuse opacity typical of ARDS. In the intensive care unit the patient developed metabolic acidosis and hypotension, and they were treated aggressively. The patient's chest radiograph was normal after 5 d; she was discharged from the hospital after 12 d. Though there are few reports of ARDS secondary to TCA, clinicians should be aware of this potential.