The incidence of tinea incognito (TI) appears to have increased over recent years, although no large series of cases has been reported in children. The aim of this study was to analyse the main epidemiological, clinical and microbiological characteristics of TI diagnosed in children in comparison with other tineas. We undertook a retrospective study of 818 tineas diagnosed in children in a referral hospital between 1977 and 2006, concentrating on TI. Of the 54 TI diagnosed, 85% were in the last 15 years. Most children were older than 9 years of age. The most usual clinical forms were tinea corporis (46.3%) and tinea faciei (38.9%). Topical steroids alone had been used to treat 68.5% of the cases. Direct examination was positive in 91.5% of the cases examined. Culture was positive in 85.2% of cases. The most frequently isolated dermatophyte was Trichophyton mentagrophytes (44.4%). This is the largest case series of childhood TI reported to date. TI has increased over recent years and important differences were found between these TI and the other tineas in children over the same period. © 2009 Blackwell Verlag GmbH.