Surgical specimens from 62 patients with vulvar dysplasia and carcinoma in situ were morphologically investigated. Lesions were classified according to WHO (mild, moderate, severe dysplasia and carcinoma in situ) and according to Toki et al. (1991) (warty, basaloid, combined warty/basaloid or basaloid/warty types or mixed (warty, basaloid and simple) forms). Following the WHO classification, moderate dysplasia was shown in 4 cases, severe dysplasia in 47 and carcinoma in situ in 11 cases. Pure warty type was shown in 2 cases (both biopsy specimens). One case revealed pure simple dysplasia whereas no case of pure basaloid type was found. Various combinations of warty and basaloid types were shown in 52 cases and mixed forms in 7 cases. The results indicate that pure forms of warty and basaloid types probably do not exist. HPV DNA was detected by PCR in 51/58 cases (88%) (45 with HPV type 16 and 6 with HPV type 33) evenly distributed in all age groups and in all types of lesions (WHO and Toki et al. 1991). By ISH HPV was detected in 24/62 cases (39%) (21 with HPV type 16/18 and 3 with HPV type 31/33), nearly always in warty areas. All these cases were positive for the same virus type by PCR. No case revealed more than one type of HPV. HPV type 6, 11, 18, and 31 were not detected by PCR. The results indicate a correlation between HPV type 16 and 33 and dysplasia/carcinoma in situ in the vulva.