Nocardia asteroides is an uncommon human pathogen typically encountered in immunocompromised patients. Primary central nervous system (CNS) nocardiosis is rare and usually manifests as cerebritis or abscesses. The case of a young woman who presented with CNS Nocardia abscesses complicated by an infective middle cerebral artery aneurysm is reported. Treatment, which included abscess aspiration, aneurysm excision, and end-to-end extracranial to intracranial bypass and prolonged antibiotic therapy, resulted in an excellent outcome. This case and the management of CNS nocardiosis are reviewed. © 1988 by the Congress of Neurological Surgeons.