Few studies have been made of the prevalence of onychomycosis among ordinary people. We therefore investigated 800 people aged between 6 and 80 years, in different age groups. We found 162 persons in whom onychomycosis was clinically suspected. However, only the 91, in whom the fungal culture was positive for dermatophytic fungi, were included in the final prevalence numbers. We found a prevalence of 13.0% in men, 4.3% in women, and 8.4% in the entire population including children. Onychomycosis was not found in any of the 200 people aged less than 20 years. The prevalences found in this study are much higher than those reported in the earlier studies made elsewhere in Europe.