Summary: We report a case of E. coli osteomyelitis of the ribs in an immunocompetent 66-year-old man. After radical surgical debridement, bone and soft-Tissue defects were covered with a rectus abdominis muscle flap. The postoperative course was uneventful, and there was no recurrence of chest symptoms. Among the various types of osteomyelitis, Gram-negative bacteria such as E. coli osteomyelitis is a relatively rare disease. Osteomyelitis is known to supervene in trauma or postoperative infection and to frequently begin with cellulitis, vascular access, endocarditis, or urinary tract infection, which spreads through the blood to the bone. To add to the difficulty of making a correct diagnosis, the early symptoms of osteomyelitis are often non-specific. We should never forget osteomyelitis in the differential diagnosis of these antecedent infections.