Background: Exfoliative dermatitis is a rare disorder with several etiologic factors. The frequency of different etiologies varies in the medical literatures. The purpose of this study was to reveal the demographic characteristic and etiologies of exfoliative dermatitis in our department.Method: We reviewed the records of the patients who were admitted to the dermatology ward of Ghaem Hospital, Mashhad, Iran, with a diagnosis of exfoliative dermatitis in a twenty-year period (1982-2002). Age, gender, the cause of exfoliative dermatitis, and the most probable drug cause were studied. Result: Fifty-nine cases were included in the study. Male-female ratio was 1.27:1. The mean age of the patients was 50.11±19.37. The most common causes were psoriasis (40.7%), drugs (18.6%) and lymphoma (18.6%). The most common drugs that caused exfoliative dermatitis were co-trimoxazole (27.27%), carbamazepine (18.18%), and gold salts (18.18%). Conclusion: The most frequent of underlying cause of exfoliative dermatitis in our series was psoriasis. Co-trimoxazole was the most common drug that caused exfoliative dermatitis.