Forty-six cases of mucoepidermoid carcinoma (MEC) of the salivary glands were reviewed with an emphasis on the clinicopathologic aspects and prognosis of the tumors. MEC occurred in a wide age range, with few cases being diagnosed in childhood. Its peak of incidence was in the fifth decade and it involved major and minor salivary glands with equal frequency; the parotid gland was the gland most commonly affected. Presence of a mass was the most common complaint of all 46 patients. About 64% of the patients presented with stages 3 and 4 disease. Three distinct histologic grades were found after analyzing cellular pleomorphism, mitotic activity, and presence of necrosis. This study showed that clinical staging and histologic grading are the most important factors influencing survival and they seem to be independent of each other. Other variables found to be important in prognosis were age, sex, and the development of recurrent disease after surgery. Surgery with total resection of the tumor was the most effective treatment in our cases and adjuvant radiotherapy proved to be of little value in improving survival of MEC in our series of cases, considering that the patients in whom this type of treatment was used had unfavorable clinicopathologic factors. HEAD 8 NECK SURGERY 8~409-417.1986 Since Foote and Frazell' classified all mucoepidermoid tumors as carcinomas, designating some From the Departments of Analomic Pathology (Drs Nascimento, Amaral, and Prado). Head and Neck Surgery (Dr Kligerman), and Epidemiology (Cr. Silveira), 1ns:ituto Nacional de CBncer, Ric de Janeiro, Brazll Address reprint requests to Dr Nascirnento at Rua Real Grandeza.