Tinea cruris is an intensely pruritic fungal infection of the groin and adjacent skin. Also known as crotch rot and jock itch, it can be a troubling important entity that at times is a clinical, diagnostic, and therapeutic challenge. Predisposing factors include heat, humidity, and hyperhidrosis, common accompaniments of high school–aged athletes. Furthermore, obesity and diabetes mellitus, additional risk factors for tinea cruris, are reaching unprecedented levels in adolescents. Treatment options range from improving hygiene to topical antifungal agents and systemic antifungal agents, the latter with potentially dangerous side effects.