Onychomycosis and tinea pedis are common superficial infections caused primarily by dermatophytes. The aim of this investigation was to study the epidemiology, etiological agents, and potential risk factors for infection based on comparison of athletes and non-athletes from a northern region of Rio Grande do Sul (Brazil). Each group consisted of 100 male individuals with ages ranging from 18 to 40 years. After a clinical examination, samples were taken from individuals presenting signs of onychomycosis and/or tinea pedis for direct microscopic examination and culture. Among the athletes, the frequency of onychomycosis and/or tinea pedis was 32%, and for the control group, it was 20%. The athletes presented 16% of onychomycosis, 12% of tinea pedis, and 4% of onychomycosis and tinea pedis together. The distribution in the control group was 10% of onychomycosis, 7% of tinea pedis, and 3% of this association. The pathogens identified were dermatophytes (84.8%) and yeasts (15.2%), and the most commonly identified organism was Trichophyton rubrum, followed by Trichophyton mentagrophytes var. interdigitale. No significant differences were found when the frequency of species distribution in the athletes and non-athlete groups was compared. Risk factors for onychomycosis in athletes included familial cases of fungal infection, contact with domestic animals, and nail trauma, while the risk factors in non-athletes included the habit of not using sandals in public bathrooms and nail trauma. For tinea pedis, the habit of not using sandals in public bathrooms was a predisposing factor in both groups, while hyperhydrosis was a risk factor only in non-athletes. This study concludes that despite the higher number of fungal infections in athletes, there is no significant difference between these groups.
