Colposcopically directed cervical biopsies, smears, and swabs obtained from 210 women with a previous abnormal cervical cytology were evaluated for the presence of human papilloma virus (HPV) using morphology and dot-blot hybridization. The diagnosis of HPV infection in biopsies and smears examined morphologically was rendered using established criteria for condyloma/cervical intraepithelial neoplasia (CIN). In hybridization studies, DNA was isolated from cells obtained from cervical swabs and annealed with probes that detected HPV types 6/11, 16/18, and 31/33/35 using a dot-blot procedure. Ninety-five cases demonstrated morphologic evidence of condyloma/CIN; 51 of these (54%) were positive for HPV DNA (five cases 6/11, 21 cases 6/18, 20 cases 31/33/35, and five cases two different probes). HPV DNA was also detected in 6 of the 115 cases (5.2%) that were morphologically negative (three cases 16/18, three cases 31/33/35). The results demonstrated that morphology was more sensitive than dot-blot hybridization for detection of HPV-related lesions. The dot-blot hybridization did detect HPV DNA in a small percentage of the cases that showed no morphologic abnormality and was useful for typing of the HPV. At this juncture, however, the clinical significance of the latter findings is unclear.