Background: An effective treatment for onychomycosis can be achieved by identifying the etiological organism and antifungal susceptibility testing. This study aimed to isolate most prevalent fungi causing onychomycosis, detecting risk factors and clinical features of the disease.

Methods: This cross-sectional prospective clinical study has been performed on 80 patients clinically diagnosed to have onychomycosis. After a careful history taking (age, sex, underlying medical conditions and possible risk factors) a nail sample was obtained and subjected to mycological examination (10% KOH microscopic examination and fungal culture for identification of causative fungi.

Results: The most frequent isolated fungi were non dermatophytes which were isolated from 42.5% of the patients followed by dermatophytes in 37.5% then candida in 7.5% of the patients. The isolated non dermatophytes were A. flavus 10% A.niger10%, A.fumigatus7%, alternaria7%, scopulariopsis7% ,Cladosporium5% , Penicillium 1%. The isolated dermatophytes were T.Rubrum 20%, T.Mentagrophytes 14%, T.interdigitale 2%, E.floccosum 2%, T verrucosum 2%.

Conclusion: The incidence of non-dermatophytes onychomycosis has been increasing recently.

non-dermatophytes are emerging pathogens of onychomycosis among patients attending Zagazig University Hospitals.