A splenectomized patient with systemic lupus erythematosus, who had previously been treated with high doses of corticosteroids, presented with headaches and symptoms of a respiratory tract infection. A magnetic resonance imaging scan of the brain revealed a ring-enhancing lesion, and Nocardia asteroides was isolated from a stereotactic biopsy specimen. After adverse reactions to a number of antibiotics, infection control was finally achieved by the new oxazolidinone drug, linezolid. Nocardiosis should be considered as a differential diagnosis in all immunocompromised patients who develop an obscure infection; delay in diagnosis and subsequent initiation of appropriate treatment often results in a fatal outcome. Linezolid is a new option for the treatment of nocardiosis and is effective when given orally.