ACTINOMYCOSIS or nocardiosis caused by Nocardia (Actinomyces) brasiliensis (Lindenberg, 1909; Castellani and Chalmers, 1913) has been reported chiefly from Brazil and Mexico with possible case reports from other Latin American countries. The organism was isolated for the first time by Lindenberg1 in Brazil, from a mycetomatous lesion of the thigh, leg, and foot, with resultant limitation in motion of the knee. The name Discomyces brasiliensis was given the organism, and then changed to Nocardia brasiliensis by Castellani and Chalmers in 1913.2 The first indication of the presence of N. brasiliensis in North America was the report of Boyd and Crutchfield,3 who described a mycetoma of the foot occurring in a Mexican. They named the organism Actinomyces mexicanus, new species, after comparing it with N. asteroides, which it imitates grossly in culture. Gonzalez Ochoa4 studied and compared strains of N. brasiliensis, N. mexicana,