BACKGROUND The aim of this study was to investigate the involvement of CMV infection in wheezing infants and the association between CMV-DNA and immunoglobulins (Igs). MATERIAL AND METHODS A total of 243 wheezing infants and 3,000 parturients were enrolled in this study. The infants were randomly grouped to receive blood HCMV-DNA tests (n=46) or urine HCMV-DNA tests (n=197). Furthermore, all participants had serum CMV-specific IgM and IgG testing. Afterwards, 10 HCMV-IgG positive infants were randomly selected for simultaneous blood and urine HCMV-DNA tests, and 25 HCMV-IgG positive puerperants were randomly selected for urine HCMV-DNA tests. RESULTS The detection rate of urine HCMV-DNA was significantly higher than that of blood HCMV-DNA (67.5% vs. 13.0%, p<0.001). Fifteen (6.2%) and 190 (80.0%) infants showed positive CMV-specific IgM and IgG results (p<0.001), respectively. Among the 10 HCMV-IgG positive infants tested further, only two infants had positive HCMV-DNA blood tests, while all of the 10 infants had positive HCMV-DNA urine tests. However, HCMV-DNA was not detected in the urine of the 25 randomly selected parturients positive for HCMV-IgG. CONCLUSIONS CMV infection may be one of the causes of wheezing in infants; CMV infection can be detected by urine-HCMV-DNA and serum HCMV-IgG testing. Infants were more susceptible to CMV infection than parturients.