The anaerobic Gram-positive bacterium Propionibacterium avidum is a common inhabitant of the skin with low pathogenicity. We report a case of P. avidum sacroilitis, psoas abscess and osteomyelitis in a 67-year-old male who had recently undergone surgical repair of an inguinal hernia. The organism was recovered from blood cultures, a bone biopsy specimen and specimens from the abscess. The spectrum of bone and joint infections caused by Propionibacterium is discussed. Infection by Propionibacterium spp. should be considered in patients with bone and joint infections.