Septic or acute bacterial arthritis is a medical emergency. The primary physician must suspect this condition even when clinical symptoms are non specific or with simultaneous inflammatory arthropathy. Septic arthritis can have serious complications. Optimal care requires hospital admission in general. Synovial fluid aspiration and its correct interpretation, the appropriate choice and timely administration of empiric antibiotic therapy can limit destruction of the joint's cartilage. The adaptation of the antibiotic regimen after reception of microbiological results and the adequate treatment in full length require interdisciplinary collaboration between the hospital physician, including the specialist in infectious diseases, the microbiology laboratory and post-hospital care.