STUDY DESIGN. This is a case report. OBJECTIVES. To the authors' knowledge, simultaneous septic arthritis of a lumbar facet joint and another joint has not been described as yet. Therefore, a patient is presented in whom both a lumbar facet joint (L4-L5 on the right) and a sternoclavicular joint were involved. SUMMARY OF BACKGROUND DATA. Septic arthritis of a lumbar facet joint is a rare condition, and only a few cases have been reported in the literature. METHODS. The etiology, clinical presentation, technical examinations, and treatment are reviewed. RESULTS. Antibiotic treatment was sufficient to heal these lesions. CONCLUSION. Antibiotic treatment was sufficient to heal these lesions.