The files of 45 human immunodeficiency virus-infected patients with ocular toxoplasmosis were reviewed, with a median follow-up of eight months. The condition was unilateral in 37 of the 45 patients (82%) and was bilateral in eight (18%). Inflammation of the anterior chamber and the vitreous was present in 32 of 53 eyes (60%) and 38 of 53 eyes (72%), respectively. Cytomegalovirus retinitis developed during the follow-up period in nine patients (20%). Cerebral toxoplasmosis was concurrently diagnosed with the ocular toxoplasmosis in 13 patients (29%). The efficacy of the combination of pyrimethamine and sulfadiazine or clindamycin was assessed in 42 patients for the induction therapy and in 38 patients for the maintenance therapy. Induction therapy was always effective within a median period of six weeks. During maintenance treatment, the 24-month relapse rates were 0.20 and 0.18 for the 50-mg/day and 25-mg/day dosage of pyrimethamine, respectively. The overall 12-month survival rate was 0.72. Our results suggested that ocular toxoplasmosis has a better ocular prognosis than cytomegalovirus retinitis, but that it requires appropriate treatment because life-threatening cerebral involvement is often associated.