Nocardiosis is a localized or systemic infection that mainly affects immunocompromised patients, with pulmonary localization being the most frequent site. The transmission comes mainly from the inhalation of spores or by direct inoculation into the skin and ocular mucosa. More than 90 species of nocardia are described, of which more than half are recognized as pathogens in humans. The best known species of medical importance are Nocanlia farrinica, Nocardia abscessus, Nocardia nova y Nocardia brasiliensis. In Chile, there have been published cases of Nocardia asteroides and Nocardia farrinica infections. Nocardia cyriacigeorgica is considered an emerging species, there being no cases previously described in our country. We present a clinical case of pulmonary nocardiosis in an acquired immunodeficiency syndrome (AIDS) patient.