Knowledge of epidemiological and mycological characteristics of onychomycosis has been noted by many authors as being an important tool for control of these fungal infections. This study seeks to improve knowledge of onychomycosis epidemiology and mycological features. Samples were taken from infected fingernails and toenails of 976 patients undergoing treatment at a respected Dermatology Center in Ceará Fortaleza, CE, Brazil. Specimens from 512 patients (52%) were positive for onychomycosis. From the culture-positive samples, yeasts of the genus
Candida
(
C. albicans,
C. tropicalis,
C. krusei,
C. parapsilosis) were dominant. The dermatophytes isolated (
Trichophyton rubrum
,
T. tonsurans,
T. mentagrophytes var.
mentagrophytes) were dominant in 46 patients (12.99%). The mould
Fusarium
spp. was isolated from 29 patients (8.19%). Yeast of the genus
Candida is the main causal factor in onychomycosis in our region. Also, the study showed the importance of performing direct examination and culture in diagnosis of onychomycosis.
