Using Southern Blot hybridization 18 invasive malignant tumours of the vulva and 2 intraepithelial vulvar neoplasias were tested for the prevalence of HPV-DNA. In 6 of 11 primary squamous carcinomas, including one carcinoma of the Bartholinic gland, HPV 16 could be identified. Contrarily, in all seven recurrent vulvar tumours examined, including 5 squamous carcinomas, 1 fibrosarcoma and 1 zylindroma, no HPV-DNA was found. No correlation existed between HPV status of the tumours and grade of differentiation or keratinization, or the tumour-stage and lymph-node status. In one tumour-invaded lymph-node HPV 16 was detected as in the corresponding primary tumour. 12 samples from tumour free abdominal skin considered as corresponding normal tissue specimens were negative for HPV-DNA. A correlation between clinical course of the disease and HPV status of the primary tumours was not observed.