Atropine is an anticholinergic drug which is used in both parental and topical routes. Topical eye-drops of atropine sulfate are used as mydriatic and cycloplegics. Parental atropine-induced delirium is well known but topical atropine eye-drop-induced delirium cases are very limited in literature. In this case report, an elderly man underwent cataract surgery and developed delirium after the use of 1% atropine sulfate eye-drops as prescribed. This case supports the notion that even atropine eye-drops can cause delirium in patients at therapeutic doses in elderly.