The authors report the frequency of the superficial mycosis among 143 children of an orphanage in the rural arca of the State of Guanabara. There were observed 21 patients with tinea pedis and 5 patients with pityriasis versicolor. All cases showed positivity by direct examination; four (19%) positive cultures were obtained from the cases of dermatophytoses and the isolated species were Trichophyton mentagraphytes and Trichophyton rubrum. The trichophytin test was made in patients with tinea pedis and 16 positive reactions developped at 48 hours. The survey emphasizes the importance of cutaneous mycoses as a public health problem and makes a comparison between the achieved data and the investigations carried out on outpatients dermatologia clinics