Septic arthritis is a serious infection that can lead to truly devastating complications. The key to minimizing irreversible damage is rapid initiation of treatment. The best results are obtained when treatment is instituted within 1 week of the onset of symptoms. Effective treatment involves antibiotics, joint drainage and decompression, and immobilization followed by rehabilitation of the affected joint. The best choice of empiric antibiotics can be made by considering the patient's age, the synovial fluid gram stain results, and any preexisting conditions (eg, alcoholism, hypogammaglobulinemia). An episode of septic arthritis requires long-term follow up to check for relapses and to assess the outcome of any residual joint damage.