We describe 4 cases of extramammary Paget's disease of the scrotum with underlying invasive carcinoma from 1997 to 1999. Three patients had metastatic inguinal lymphadenopathy. The delay in diagnosis was significant (mean 1 year). The diagnosis was made by skin biopsy in all patients. Histologically, intraepidermal cells with enlarged vesicular nuclei and vacuolated cytoplasm, which was mucin positive, were found. The mainstay of treatment is wide surgical excision, but positive margins remain a major problem. Other modes of treatment have been advocated but the efficacy for invasive disease is low. The key to successful control of the disease is therefore a high index of suspicion and early diagnosis.