Endophthalmitis is a serious disease with multiple aetiologies. Its development seems to be dependent upon various risk factors. Among 99 cases of endophthalmitis, 79% were secondary to intraocular surgery especially cataract surgery and perforating ocular trauma. To identify risk factors of post-cataract surgery endophthalmitis, we performed a case-control study: 55 cases and 269 controls were used. Five risk factors were identified: duration of the operative procedure longer than 60 min, suture dehiscence, persistence of lens mass, traumatic cataract and left eye operated. The importance of prevention of endophthalmitis by avoiding such risk factors is raised.