In a retrospective review of laboratory records at the Department of Mycology, National Institute of Microbiology "Dr. Carlos G. Malbrán", during the period June 1989-July 1991, 1225 putatively immunocompetent cases of superficial mycoses were identified. Ninety five percent of these patients were adults and 5% children. Among the total cases, dermatomycoses were caused, 67.6% by dermatophytes, 25.9% by yeasts, 5.9% by Malassezia furfur. and 0.5% by other fungi, as proven by the isolation of the etiological agents. (Figure 1, Table 2). Among the dermatophytes Trichophyton rubrum and Trichophyton mentagrophytes greatly predominated accounting for 66.6% and 20.0% of the isolates, respectively, whereas Microsporum canis (8.0%). Epidermophyton floccosum (5.1%) and Microsporum gypseum (0.3%) were found with less frequency (Figure 2). Nails (47%) were the most common source of isolates in adults, followed by feet (28%), smooth skin (15%), groin (5%) and hands (2%) (Table 1). Regarding the relative efficiency of the diagnostic methods, the analyses of laboratory results evidenced that, 98% of the cases with clinical findings compatible with mycoses and 76% of the cases with positive cultures (Table 1) were identified by microscopic observation.