Of 100 cases of Paget's disease of the breast admitted to the National Career Institute of Milan from 1940 to 1974, 91 were statistically evaluated. They were divided in two groups according to presence or absence of a palpable nodule. The results of surgical treatment in terms of 5 and 10 year survival rates were 59 and 44%, respectively, with a median survival of 9 years. For the two separate subgroups, those with a palpable nodule were 38 and 22% for 5 and 10 years, respectively, while those without a palpable nodule were 92 and 82% for 5 and 10 years, respectively. For the two groups the median survival was 3.6 and 16.4 years, respectively. The extent of surgery should be dependent on the presence of absence of palpable nodules under the nipple. For the two groups (with and without) extended radical mastectomy and the Patey-Dawson mastectomy are recommended.