The association between the human papillomavirus (HPV) and malignant neoplasms of the uterine cervix is well established; however, its role in the pathogenesis of vulvar cancer has not been well defined. This study correlates the clinical and histopathologic features of 21 invasive carcinomas of the vulva with the presence of HPV DNA as detected by Southern blot and polymerase chain reaction (PCR) analysis. By one or both techniques, HPV DNA was detected in 10 of the 21 tumors analyzed; all HPVs containing tumors hybridized with HPV-16 probes, although PCR also detected HPV-6 in two of the HPV-16-containing tumors. No HPV-18 DNA was detected in any tumor by PCR or Southern blot hybridization. Both the invasive cancer and the surrounding intraepithelial disease tended to display histopathologic features that usually could distinguish HPV-associated cancers from those without HPV DNA. The intraepithelial lesions associated with HPV-containing tumors were of the bowenoid type with koilocytosis, while tumors lacking HPV generally demonstrated a simplex type of intraepithelial lesion. Invasive tumors with no viral DNA were more frequently keratinizing than the HPV-containing cancers. Race, parity, hormonal therapy, and alcohol use did not affect the HPV status; however, HPV DNA was more prevalent in the tumors of younger women and in those with a history of tobacco use. Human papillomavirus status had no impact on the stage of disease or its prognosis. These findings identify two subsets of vulvar carcinoma cases based on HPV hybridization data and the histopathologic characteristics of the tumor.