The medical record of a 25-year-old male hybrid lion weighing 154 kg named Tippu, with a history of blindness in the right eye since one year housed at Anna Zoological Park, Vandalur Zoo in Chennai, India was referred to the Ophthalmology Unit of Madras Veterinary College Teaching Hospital for expert opinion and treatment. As per the request from the zoo authority, a team of surgeons from Madras Veterinary College visited the zoo. The lion was immobilized with xylazine hydrochloride, 1.5 mg/kg body weight, and ketamine hydrochloride, 2.5 mg/kg body weight intramuscularly were given by using a darting gun and a detailed ophthalmic and neurological examinations, ophthalmoscopy and tonometry were performed. The condition was diagnosed as a unilateral cataract of the right eye (OD) and the most appropriate surgical correction by the Phacoemulsification method was advised. The lion was intubated with a No. 18 cuffed endotracheal tube and general anesthesia was maintained with 2% Isoflurane in oxygen. The surgical procedure was carried out using one-handed phacoemulsification and the nucleus is fragmented into four pieces. At the end of the procedure, yohimbine hydrochloride was administered 0.1 mg/kg body weight intravenously. Mild fibrin deposition was noticed in the anterior chamber postoperatively for four weeks, after which the lion showed an uneventful recovery.