It is now generally recognized that systemic infection with organisms of the Salmonella group is not of rare occurrence. The literature abounds with reports of cases involving almost every system of the body. Most of the reported cases have been of the acute toxic type with severe constitutional reactions, and the patients have been chiefly infants and children. Few if any of the cases reported deal with the chronic form of the disease, i.e., a localized pyogenic infection. Recently we encountered an unusual example of chronic bone infection involving the lower end of the tibia which proved to be of the Salmonella type. Case Report S. S., male, age 20, was referred for x-ray examination of the left ankle region. In 1940, while playing ball, he had twisted his ankle and it became painful and swollen. After a short course of baking and diathermy by his family physician the ankle became normal. Some six months later a similar episode occurred after slight activity, and this was repeated from time to time. In 1942, x-ray studies revealed a cystic degenerative process involving the metaphyseal portion of the tibia and extending into the internal malleolus. In spite of this, the patient was inducted into the Armed Forces in 1943. While he was undergoing basic training, the ankle suddenly became swollen and a cellulitis developed, requiring incision and drainage. After several weeks the lesion healed, and shortly afterward the patient was given a medical discharge. In April of 1945, while he was at college, pain and swelling of the ankle again occurred spontaneously. He returned to his home and x-ray studies again revealed cystic changes in the lower tibia. The patient gave no history of any past acute infection, food poisoning, typhoid fever, or paratyphoid infection. Aside from a mild form of “swollen glands” in childhood, he had always been perfectly well. A physical examination was negative, except for the local findings. There were moderate soft-tissue swelling and redness about the ankle region, with an old scar over the medial aspect of the ankle, the result of previous incision and drainage. Motion of the ankle was partially restricted in all directions and there was marked tenderness over the anterior and medial aspect of the lower end of the tibia. X -ray examination revealed several irregular areas of cystic change in the lower end of the tibia extending into the internal malleolus. The larger cystic area was oval in shape, fairly well defined, presenting some reactive changes in the walls. The smaller absorptive areas were less clearly defined and showed only slight reactive changes. There was no expansion of the shaft, and the cortices appeared intact. The ankle joint was preserved. The impression was that of multiple small bone abscesses. Differential Diagnosis: Giant-cell tumor was considered in the differential diagnosis because of the location of the lesion in the metaphyseal and epiphyseal end of the tibia.