Abstract. Infections caused by Human Cytomegalovirus (HCMV) are very common in patients who undergo immunosuppression or immunocompromisation. The techniques used for routine HCMV detection are timeconsuming and lack specificity and sensitivity. The ability of the Polymerase Chain Reaction (PCR) to amplify HCMV DNA from clinical samples of the patients is a valuable diagnostic tool for the detection of HCMV in the early stages of the infection. We used a pair of primers to amplify a 435 bp region of the immediate early-1 gene, to detect HCMV DNA in clinical samples from patients at high risk for HCMV infection. We found HCMV in the following type of patients: 6 out of 20 in immunosuppressed, 11 out of 31 in immunocompromised, 5 out of 8 in pregnant women, 4 out of 25 in patients with high anti-CMV IgM and IgG titres, 1 out of 2 in patients with kidney failure, and 6 out of 14 in patients with opthalmic disorders. Sixty-seven specimens, which were found to be negative for CMV by the PCR technique, were used to inoculate human fibroblast monolayer cultures and PCR was performed to the DNA extracted from the cultured cells. Only in 1 out of the 67 cases HCMV DNA was detected.