This is a monograph on suppurative arthritis in infancy and childhood based on the author's experience in 27 instances. He concludes that the disease is uncommon in children and that the Pneumococcus is the most frequent etiologic organism, followed by the Staphylococcus, streptococcus and gonococcus. The condition usually is preceded by lesions elsewhere in the body. The prognosis is good, and the only complications are subluxation of the joint, although if the suppuration occurs in the hip joint there may be destruction of important structures. The medical treatment is with sulfonamide compounds, and the surgical is immobilization with puncture or, if necessary, a simple incision.