Three patients with chronic meningitis apparently were infected with the common skin commensal, Propionibacterium acnes. Although this organism is a common culture contaminant, actual infection with P. acnes appears likely in our cases, either as secondary to another primary meningeal inflammatory disease or as the primary etiology. We suggest that P. acnes may be a cause of chronic meningitis in man. Further reports appear necessary to better establish and clarify the pathogenetic role played by P. acnes when isolated in chronic, occult infection in the central nervous system.