The data are taken from a retrospective study of 24 patients with AIDS who developed CMV disease. This study was performed to detect the principal characteristics associated with the development of CMV disease. Age, sex, risk factors, the time interval between HIV seropositivity to CMV disease were examined, as well as efficacy of gancyclovir therapy in both groups of patients with symptomatic and asymptomatic retinitis. When the chorioretinitis is still asymptomatic the early treatment of CMV disease may suppress progression of retinic lesions and seems to be efficacious to prevent the evolution of CMV disease.