Background: Getting access to information about expansion and spread of skin diseases and determination of common types of them in any specific area has particular importance. There is no doubt that cultural, social and genetic factors by an important role in the epidemiology of skin diseases. Objective: To determine the frequency of various skin diseases in patients referred to Sadooghi hospital in Yazd in the summer of year 1999. Patients and Methods: This descriptive study was done on 1000 patients who referred to the skin clinic. Final clinical diagnosis of patients were classified according to ICD 10. Results: According to ICD 10, more than 60 diseases were diagnosed among which infectious diseases of skin were the commonest (23%) and viral diseases formed about one third of total infections. 19% of cases had dermatitis of which 2 third were contact dermatitis. 10.8% of cases had acne and 7.8% had melasma. In patients under 15 years of age infectious diseases and in patients 15-25 years of age acne were the most commonly found diseases. Cutaneous leishmaniasis, which is endemic in the study area, was the most common parasitic skin infection. Conclusion: Infectious diseases and dermatitis are among the most commonly diagnosed skin diseases in Yazd and need to be considered carefully to make a comprehensive plan to control.