We have reviewed the outstanding facts about mycetoma, including the history, first reports in India, the different causal agents according to their geographic distribution, mycologic characteristics, pathology, microbiology, behavior, evolution, immunology, experimental inoculations, associated bacterial complications, and osseous lesions. Various drugs available for treatment are mentioned and recommended. Therapeutic results depend on the age of the disease, and, above all, the bony involvement. N. brasiliensis mycetoma is one of the most frequent species and causes the greatest number of mycetoma cases in America, especially in Mexico.