Background: Onychomycosis is a world-wide public health concern in children, requiring epidemiological data for different regions for control and prevention. Aim: The aim of this study was to evaluate the predominant pathogens and risk factors for onychomycosis in school children living in Kayseri, Turkey. Methods: This study included 8122 school children, aged 5-16 years, living in the rural and urban areas around Kayseri. Onychomycosis was clinically classified as distal and lateral subungual (DLSO), proximal subungual, superficial white, endonyx and totally dystrophic onychomycosis. Nail samples from children with clinically diagnosed onychomycosis were collected, examined by direct microscopy and inoculated for culture study. The demographic features and possible risk factors were recorded and assessed by logistic regression models. Results: We clinically diagnosed onychomycosis in 152 out of 8,122 (0.18%) school children. DLSO was the most frequent clinical diagnosis (120/152, 78.9%). Culture-positive onychomycosis was detected in 27/152 (17.7%) children. The prevalence of culture-positive onychomycosis was determined as 0.33%. All culture-positive samples were only from toenails. The onychomycosis causative agents were dermatophytes in 17/27 cases (62.9%), including Trichophyton rubrum 12 (44.4%), Trichophyton mentagrophytes 1 (3.7%), Trichophyton tonsurans 1 (3.7%) and Trichophyton spp. 3 (11.1%) and yeasts in 10/27 cases (37.1%), including Candida glabrata 4 (14.8%), Candida parapsilosis 1 (3.7%), Trichosporon 2 (7.4%) and Rhodotorula 3 (11.1%). Age, father's occupation, number of siblings and rooms were statistically associated with the frequency of onychomycosis. Conclusions: Although to be prevalence of onychomycosis in school children in central Anatolia of Turkey seems very low degree, pediatric onychomycosis is a growing public health concern all over the world. Children having more siblings or unemployed fathers and children living in small house as well as older children should be examined carefully for onychomycosis.