An "in house" qualitative polymerase chain reaction (PCR) assay was used for detection of cytomegalovirus (CMV) DNA in 64 blood samples from 61 HIV-infected patients with CD4 T-cell counts below 250/mm(3). Twenty-five patients presented positive results indicating CMV infection, however, only 3 patients presented clinical symptoms related to CMV disease at the time of blood collection. The sensitivity, specificity, and positive and negative predictive values for the PCR assay were 100%, 95%, 12%, and 100%, respectively. Despite the low positive predictive value, the qualitative PCR still appears to be a good marker for initiating preemptive treatment.