This study included 10 random finger-nail onychomycosis cases attending the Demiatology out-patient Clinic of Sohag University Hospital. The age of patients rangedfront 21-65 years with a mean of 44.6±13.4 years. The sex ratio is 1:1. Clinical examination revealed that Proximal Subungual Onychomycosis (PSO) was detected in 10% of cases and Distal and Lateral Subungual Onvchontycosis (DLSO) in 90% of cases. Nail specimen was taken and subjected to direct microscopy, culture and Scanning Electron Microscopy (SEM). We found that 60% of cases showed positively for fungus by direct microscopy, while culture was positive in 80% and SEM was positive in 70%. The isolated fungi were rubrum in 4 cases while Aspergillus niger as cultured in 4 cases. We concluded that the correlation between clinical, direct microscopy,culture and SEM had an essential role in the diagnosis of onychomvcosis