Dermatophytoses are considered to be one of the major public health problems in the world and are among the most commonly diagnosed skin diseases in Iran. In spite of improved personal hygiene and living environment, dermatophytosis continues to spread and persist. To determine the prevalence of dermatophytosis and their etiologic agents in Mashhad (Iran), five hundred and sixty patients suspected to have fungal infection were studied. Subjects who participated in this study were 330 males and 230 females ranged in age from 4 months to 70 years with a mean age of about 25.5 years. Clinical materials including skin scraping, hair and scalp sample, nail clipping and subungual debris were collected. All of the specimens were assessed by direct examination and culture. Of 560 patients, 166 (29.6 %) had dermatophytosis. The types of tinea according to anatomical areas were as follows: tinea corporis (33.1 %), tinea capitis (32.5 %), tinea manuum (17.5 %), tinea cruris (10.2 %), tinea pedis (5.4 %), tinea unguium (0.6 %) and tinea barbae (0.6 %). Trichophyton verrucosum was the most prevalent species followed by Trichophyton violaceum and Trichophyton mentagrophytes. The prevalence of dermatophytosis in males was higher than in females. Based on a review of published studies from different parts of Iran, there are regional differences in the incidence of dermatophytosis. Epidermophyton floccosum has been the most prevalent species, and Microsporum canis has been isolated less than from the other countries.