Dermatophytes are worldwide in distribution and dermatophytosis is a common problem in developing countries. It can occur in both sexes and all ages but the diseases are more common in school children. This study attempted to determine the prevalence and etiological agents of dermatophyte infections of hair, skin, and nail among primary school children in Harari Regional State from April to June 2015. A cross-sectional study was conducted on 428 primary school children. Skin scrapings, hair samples, and nail clippings were collected from children who showed dermatophytosis. All specimens were subjected to microscopic examination and culture. Following a meticulous collection, data was analysed using SPSS version 21. Of the 428 school children, 211 (49%) male and 217 (51%) female, 100 (23.4%) had culture confirmed dermatophytosis and tinea capitis took the overall prevalence of 18% (77/428). Trichophyton violaceum was isolated from 43 samples, followed by Trichophyton rubrum in 24. The highest prevalence of dermatophytosis was seen in the age group 5-9 years and grade levels of 1-2 ( < 0.05). As a result, this study found a high prevalence of dermatophytosis in the Harari's Regional State school children and tinea capitis was the predominant clinical finding which needs an intervention.