The recognition of both overt and subclinical vulvar HPV infection has become increasingly important. However, although molecular biological evidence has indicated a strong link between HPVs and cancer, clinical or epidemiological evidence is still not fully convincing. We studied 159 HPV DNA positive patients, using a dot blot hybridization technique (ViraPap and ViraType, Digene Diagnostics. USA), and 69 randomly selected HPV negative controls drawn from the same clinical setting, at the outpatient clinic, Department of Obstetrics and Gynecology, University Central Hospital, Helsinki, Finland. Seven patients had HPV 6/11, 51 had HPV 16/18, 52 had HPV 31/33/35 25 had more than one of the three HPV DNA groups ("mixed"), and 24 had untypable HPV DNA. Cases and controls were examined at four month intervals. The mean follow-up time was 12.2 months (SD 8.7) for the cases, and 12.8 (SD 6.9) for the controls. Although vulvar or vaginal abnormalities (acetowhite epithelium, squamous papillomatosis, filaments, satellite lesions, fissure, papules, or exophytic condylomas) were more commonly seen in the cases than in the controls, the difference was significant only for exophytic condylomas. In conclusion, colposcopy is not a good predictor of HPV infection and should not be used as an HPV screening test. HPV DNA hybrodization did not help more than the histopathologic findings in the diagnosis, but allowed the recognition of high-risk patients. The role of an accurate colposcopic examination with target biopsies remains essential.