Clinical data were retrieved from the hospital records of 34 patients with Paget's disease of the vulva treated from 1972 to 1990. Flow-cytometric (FCM) DNA measurements and p53 and c-erbB-2 immunostaining were performed on paraffin-embedded samples. Five patients had an underlying adenocarcinoma and 29 intraepithelial disease (IEP). Twenty-seven patients with IEP underwent surgery. The surgical margins were positive in 15 patients, negative in 10, and not evaluable in 2. The tumor was diploid in 15 patients, nondiploid in 11, and not evaluable in 1. Eight patients recurred, 6/15 (40%) with positive and 2/10 (20%) with negative margins. One patient with positive margins was never disease-free. Recurrence was seen in 6/11 (55%) patients with nondiploid tumors, 4 with positive and 2 with negative margins. Two of 15 (13%) patients with diploid tumors recurred/persisted, both with positive margins. None of the 6 patients with diploid tumors and negative margins recurred. p53 and c-erbB-2 were found negative in all but 4 patients. Tumor nondiploidy was associated with an increased risk of recurrence irrespective of surgical radicality. p53 and c-erbB-2 seemed to play no role in the pathogenesis or prognosis.