Rhodococcus equi is an intracellular facultative, gram-positive, partially acid-fast, cocco-bacillary microorganism of increasing importance as a pathogen in severely immunocompromised HIV-positive patients. Rhodococcus equi may cause invasive pulmonary infection, bacteremia and disseminated infection. Rhodococcus equi is easily cultured from blood or sputum on standard media, but is frequently regarded as a contaminant. Delay in establishing a definite diagnosis may result in a poor outcome in most cases. Treatment in humans is not standardized. Surgical intervention may be beneficial in selected cases.