Acute bacterial arthritis usually is caused by gonococcal or nongonococcal infection of the joints. Nongonococcal and gonococcal arthritis are the most potentially dangerous and destructive forms of acute arthritis. These bacterial infections of the joints are usually curable with treatment, but morbidity and mortality are still significant in patients who have underlying rheumatoid arthritis, patients who have prosthetic joints, elderly patients, and patients who have severe and multiple comorbidities. This article reviews the risk factors, pathogenesis, clinical manifestations, diagnosis, and treatment of nongonococcal and gonococcal arthritis.