To investigate the possibility of sexual transmission of human papillomavirus (HPV), 53 married couples were examined for the presence of HPV-16 and -18 DNAs in the uterine cervix and semen using the polymerase chain reaction method. Twenty-three of the 53 women and 12 of the 53 male partners were positive for HPV-16 DNA. No HPV-18 DNA was detected in samples from any of the partners. In 27 pairs, both partners were negative for HPV DNA in cervix or semen; in the remaining 26 pairs, at least 1 of the partners was HPV-16-positive. In 9 (35%) of these 26 pairs, both partners were infected. Furthermore, 9 (75%) of the 12 women with HPV-positive partners were HPV-positive, while 9 (39%) of the 23 men with HPV-positive female partners were HPV-positive. These findings suggest an increased risk of HPV transmission via sexual intercourse, thereby underscoring the importance of preventive care against HPV infection during intercourse.