A mycetoma is a chronic granulomatous infection of the skin and subcutaneous tissue from which grains of the causative organism are eliminated through sinus tracts. In a patient with a suspected mycetoma, evaluation should include (1) elicitation of a history of trauma, (2) determination of the presence of the clinical triad of swelling, sinus tracts, and extrusion of grains, (3) roentgenographic examination, (4) examination of the grains, (5) histopathologic study, and (6) culture. Identification of the causative organism is important for guiding therapy; etiologic agents include actinomycetes, eumycetes, eubacteria, and dermatophytes. Whereas surgical treatment is still usually required for eumycetomas, various chemotherapeutic agents have shown promising results in the other types of mycetoma.