Eccrine porocarcinoma is a rare, malignant neoplasm of eccrine sweat glands. It often occurs in elderly people, mean age of 67.5 years. The clinical features are variable and their localization is not related to sweat-gland concentration, occurring mainly on the feet and legs. Disease diagnosis and treatment should be as early as possible in order to avoid tumor aggressiveness that occurs in 20% of the cases. The authors present a case of extensive porocarcinoma on the thorax of a 71-year-old male patient.