Cytomegalovirus (CMV) infection remains a life-threatening infection in patients with HIV disease. A rapid, quantitative diagnostic technique is needed to adi in the diagnosis of CMV disease. This study was undertaken to evaluate the CMV antigenemia test in patients with HIV disease who are at risk for CMV disease. The study included 22 patients who underwent ophthalmologic exams or selected diagnostic techniques in whom CMV cultures and CMV antigenemia tests were performed. All of 11 patients with CMV disease had positive CMV antigenemia assays [range, 48-1,000 positive cells/2 x 10(5) peripheral blood leukocytes (PBL)], and 10 were also CMV viremic. There was no clinical evidence of CMV disease in 11 patients, including seven in whom the CMV antigenemia assay was negative and who remained without evidence of CMV disease after a median follow-up of 159 days. Four patients had low antigenemia levels. Of these four, two subsequently developed CMV retinitis. In conclusion, a positive CMV antigenemia result with > or = 48 positive cells/2 x 10(5) PBL correlated with concurrent CMV disease. The CMV antigenemia test appears to be a valuable tool for the rapid diagnosis of CMV disease in HIV-infected individuals.