Maduromycosis is a rare fungal infection in the northern United States, most frequently caused by Allescheria boydii, usually in debilitated or immunosuppressed patients. An 18-year-old Mexican-American, in excellent health, developed multiple draining sinuses at the sites of insertion of Ender nails for a closed tibial fracture. Madurella mycetomi was cultured from black granules in a biopsy specimen. The source of fungal infection remained unknown, although it probably did not occur during the surgical procedure. Since no specific antibiotic treatment is available, it is possible that with progression of the infection, amputation may be necessary in the future.