In this case, the bacillus-pyocyaneus infection developed in an area of first and second degree burn of the leg. Subsequently, the infection involved the soft tissues about the ankle joint, followed by roentgenographic evidence of destruction of the distal tibial epiphysis on the right. Fifteen months after recovery, a pyarthrosis of the same ankle developed, from which a pure culture of bacillus pyocyaneus was obtained. Recovery ensued after incision and drainage of the ankle and autogenous-vaccine therapy.