Tracheobronchial foreign body aspiration can cause serious health problems in individuals of all age groups and requires immediate diagnosis and intervention. Patients with psychiatric disorders can aspirate foreign objects that may pose a danger to their health. Herein, we report on a case of curtain clip aspiration in a 44-year-old man with mental retardation. Chest radiography and bronchoscopy showed a sharp, pointed, S-shaped curtain clip inversely lodged in his left main bronchus. The curtain clip was removed successfully using flexible bronchoscopy, and no complications were noted.