Mycetoma is a chronic, granulomatous, subcutaneous, inflammatory disease caused by true fungi (eumycetoma) or filamentous bacteria (actinomycetoma). It occurs in the mycetoma belt stretching between the latitudes of 15 degrees South and 30 degrees North and is endemic in relatively arid areas. The organisms are present in the soil and may enter the subcutaneous tissue by traumatic inoculation. Mycetoma commonly affects adults aged 20 to 40 years, predominantly males. The foot is most commonly affected. Both forms of mycetoma present as a progressive, subcutaneous swelling, although actinomycetoma has a more rapid course. Multiple nodules develop which may suppurate and drain through sinuses, discharging grains during the active phase of the disease. Diagnosis may involve radiology, ultrasonic imaging, cytology, culture, histology or immunodiagnosis. Actinomycetoma is amenable to treatment by antibiotics, preferably by combined drug therapy for long periods. Eumycetoma is usually treated by aggressive surgical excision combined with medical treatment.