OBJECTIVE: To study the relationship between the nephrotic syndrome(NS) and active infection with human cytomegalovirus (HCMV). METHODS: HCMV-DNA in peripheral leukocytes from 36 cases of NS was detected with the polymerase chain reaction (PCR) technique. HCMV-IgM antibody detection was done using ELISA simultaneously. RESULTS: The positive rates of active HCMV-IgM antibody and HCMV-DNA were 30.5% and 38.9%, respectively, higher than those of the control group (both P<0.01). HCMV-IgM and HCMV-DNA were found simultaneously positive in 8 cases. CONCLUSIONS: Some children with NS have HCMV infection.