Pneumocystis carinii pneumonia is a major cause of morbidity and mortality in patients with the acquired immunodeficiency syndrome. When P. carinii is disseminated, the choroid may be involved and the infection is often fatal. We examined, treated, and followed up two patients who developed choroidal lesions typical of P. carinii while taking aerosolized pentamidine for prophylaxis. The choroidal lesions gradually resolved after three weeks of therapy with intravenous trimethoprim and sulfamethoxazole in one patient, and after three weeks of therapy with parenteral pentamidine in the other patient. The patients did not have clinical or laboratory evidence of P. carinii infection other than in the eye. It thus appears that early ophthalmologic examination may detect disease before it is threatening to sight and allow systemic therapy to be instituted before widely disseminated infection results in a fatal outcome.