To investigate the correlation between human papillomavirus (HPV) infection and cell proliferative activity in uterine cervical adenocarcinoma, in situ hybridization of HPV DNA and immunostaining of proliferative cell nuclear antigen (PCNA) were performed on serial sections of the carcinoma. HPV 16 and 18 DNA was detected in 10 of 33 cases of cervical adenocarcinoma and adenocarcinoma in situ. PCNA was detected in 30 cases. In all 10 HPV-positive cases, PCNA was also demonstrated, and the number of PCNA-positive cells tended to be higher than that in HPV-negative cases. With 1:1 correlation between HPV and PCNA on the nuclei, the coincidence rate was 72% (p < 0.01). These results indicate that HPVs play a role in cell proliferation.