Thirteen consecutive cases of vulvar Paget's disease treated by us between 1975 and 1984 underwent pathologic retrospective review. In the first group of eight patients having Paget's disease not involving the anal mucosa, the extent of disease was completely defined by frozen-section margins. Additional intraoperative resections were necessary in five of the eight. None had residual involvement on permanent sections and none had recurrences in 3 to 8 years of follow-up, although two died of unrelated causes. A second group of two patients early in the series had frozen sections to define some but not all of the margins. Both had positive perineal margins on permanent sections. One has required two subsequent revisions after 3 years of follow-up and the other has been free of disease during 9 years of follow-up. A third group of three patients all had anal mucosal involvement and all had associated mucinous adenocarcinoma of the rectum. Frozen sections actually discovered the presence of one of the three carcinomas. After appropriate radical operations, all three are alive and free of disease between 2 and 9 years of follow-up. It is concluded: patients with vulvar Paget's disease can reduce the need for subsequent operations with the use of frozen sections to define surgical margins; anal mucosal involvement of Paget's disease represents an ominous sign of underlying carcinoma.