Objective To evaluate the clinical features, diagnosis, and outcome of the treatment of cytomegalovirus (CMV) retinitis, and the relationship between CMV retinitis and acquired immunodeficiency syndrome (AIDS). Methods A total of 95 eyes of 56 patients with cytomegalovirus retinitis and AIDS were studied. The fundus feature, visual acuity and CD4+ T-lymphocyte counts were analyzed and the follow-up periods ranged from 2 weeks to 18 months. Results Before the definitive diagnosis of CMV retinitis, the courses of AIDS were 4 to 26 months in all patients. In the initial examination, the granular form of CMV retinal lesion was noted in 55 eyes (57%) in which retinal lesion of 46 eyes was peripheral. The fulminant form of CMV retinitis of 25 eyes (26%) was found in the posterior pole and consisted of densely opaque retinal lesions with blotchy hemorrhage and vasculitis. The overlap between these two presentations was noted in 15 eyes. Papillitis was observed in 7 eyes of CMV retinitis in this series of patients. The visual acuity ranged from finger counting to 0.5. The patients with extensive CMV retinitis or CMV retinitis in the posterior pole got poorer vision. The CD4+ T-lymphocyte counts of 30 patients was 0-30 (mean, 15±9/μl), and the survival time ranged from 2 weeks to 18 months (mean, 6.4±3.3 months). The vision was improved and CD4+ T-lymphocyte counts was significantly higher in the group treated with ganciclovir, and progression of CMV retinitis occured and the vision decreased in the non-treated group. Conclusion CMV retinitis is the most common intraocular complication in patients with AIDS. Diagnosis of CMV retinitis is based on the characteristic of necrotizing retinitis which was typically associated with retinal hemorrhage and vasculitis. Ganciclovir is effective for the treatment of CMV retinitis. (Chin J Ocul Fundus Dis, 2002, 18: 89-91)