Rhodococcus equiis an aerobic, intracellular, gram-positive rod-eoccus that is partially acid fast. The organism is primarily a pathogen in animals and has only rarely been seen in immunocompromised humans. Its most common manifestation is a slowly progressive pneumonia that may cavitate. Infections are thought to beacquired via respiratory exposure to animals or soil. R. equi infections are difficult to treat, usually requiring prolonged administration of parenteral antibiotics and often necessitating surgical drainage. A case of cavitary pneumonia and recurrent bacteremia with R. equi in a patient with AIDS is reported, and the current literature on R. equi infections in humans is reviewed.