Tinea capitis is a dermatosis of the scalp due to dermatophytes that can cause hair loss. It remains a significant endemic problem mainly in school children in tropical regions. The purpose of this case-control study carried out in the Dermatology Center of Treichville Hospital was to identify risk factors for tinea capitis in Abidjan, Cote d'Ivoire. A total of 80 cases were recruited on the basis of clinical findings showing one or several plaques showing desquamation or parakeratosis suggestive of tinea capitis. Diagnosis was confirmed by mycology using samples seeded on Sabouraud-chloramphenicol glucose agar and incubated at 27 degrees C for a mean period of 15 days. Species identification was based on growth rate, macroscopic aspect of isolates, production and potential diffusion of pigment, and microscopic examination. Controls were the next patient of the same age and sex with no evidence of mycosis. All subjects were questioned about previous history of mycosis, duration of tinea capitis lesions, functional signs, grooming habits, and pet-keeping. Size of selection was calculated by epi info 6.04 fr according to following estimations: percentage of exposed subjects in control group: 30%; percentage of exposed subjects in case group: 50%; probability threshold of 5% to find a difference between case and control groups even though there was no difference; and probability threshold of 20% to find no difference between cases and controls even though there was a difference. Study findings demonstrated a 3 times higher incidence of tinea capitis in boys than in girls and a peak during childhood especially between the of 5 to 9. The most frequent etiologic agents were Trichophyton soudanense and Microsporum langeroniise. Subjects at highest risk lived in dwellings having less than 4 rooms, used soap to wash the hair, cut their hair with a blade, and had low income.