Although effective therapies for nail fungal infections are now available, there have been no recent epidemiological surveys, to our knowledge, of onychomycosis in the United States. In a representative sample of 20 000 individuals aged 1 to 74 years in the northeastern United States in the late 1970s, the US Health and Nutrition Examination Survey found the overall prevalence of nail fungal infections to be 2.18%.1More recently, population-based questionnaire surveys conducted in the United Kingdom2and Spain3found the overall prevalence of onychomycosis to be 2.7% (males, 2.8% and females, 2.6%) and 1.7% (males, 0.8% and females, 1.8%), respectively. Heikkila and Stubb4investigated 800 individuals aged 6 to 80 years in Finland. In contrast to the previously mentioned studies, individuals were examined by a dermatologist and the diagnosis was confirmed by a fungal culture positive for dermatophytes. This study's results yielded a higher onychomycosis prevalence of