Tinea capitis is the most common superficial mycosis in children of school age. Although it is of public health importance, it is not a reportable or notifiable disease; therefore, actual prevalence figures are unknown in many endemic areas. The aim of this work was to determine the prevalence of tinea capitis among primary school children in two states in central Nigeria, highlighting the main aetiological agents of the infection and possible predisposing factors. A total of 28 505 primary school children aged between 3 and 16 years were recruited for the study, from 12 primary schools in two local government areas of Benue and Plateau States of Nigeria. Of them, 796 had lesions, which were clinically suggestive of tinea capitis out of which 248 (31.2%) were confirmed positive by microscopy and culture. Tinea capitis was more frequent in males, 194 (78.2%) than in females, 54 (21.8%). Children aged 10-14 years, followed by 5-9 years were predominantly infected, with 106 (42.7%) and 100 (40.3%) respectively. There was a significant correlation between age group and occurrence of tinea capitis in the study population at 95% confidence level (P = 0.004). Tinea capitis was significantly more frequent in Jos State (44.6%) than in Gboko State (23.2%) (t = .659; 95% confidence level). The prevalence of tinea capitis was influenced by social and cultural habits of the areas rather than by population density. The aetiological agent of tinea capitis in the study population was Trichophyton soudanense, 76 (30.6%), followed by Microsporum ferrugineum, 19 (7.7%) and Microsporum audouinii, 19 (7.7%). Differences in aetiology were observed for Gboko and Jos, except for T. soudanense, which predominated in both areas. The high prevalence of tinea capitis in the areas studied may be attributed to frequent interaction with soil and animals and low level of health education on personal and environmental hygiene. Aetiological agents varied from one geographical area to another.