An unusual destructive lesion of the talus, considered to be of leprous origin, was recently observed in two patients at the National Leprosarium, Carville, La. (1). Both had lepromatous leprosy of several years duration. Secondary neural manifestations were minimal, and no coexistent disease was present. The clinical circumstances under which the lesion developed, its roentgen appearance, and its tendency toward regeneration suggest an infectious origin rather than the neurotrophic absorptive phenomenon seen so commonly in the more peripheral bones of the hands and feet in leprosy. Clinically, the lesion was of insidious onset, manifesting itself during prolonged lepra reactions by intermittent pain and swelling in the ankle region. Roentgenologically, bone changes in the early stages were difficult to detect, and not until the pain and swelling became persistent was the destructive process demonstrable. It consisted of a small area of decreased density, of moth-eaten appearance, in the inferior portion of the neck and head of the talus. The lesion gradually increased in size over a period of several weeks until the entire neck and head of the bone were involved. In one patient the lesion did not extend further; in the other, presumably because of premature weight-bearing, the destructive process continued through the articulating cartilage into the talocalcaneonavicular articulation. In this latter instance, a deformity resulted similar to that seen in fracture of the neck of the talus—a splay foot with flattening of the longitudinal arch and abduction of the anterior part of the foot at the mid-tarsal joint. Suppuration, as far as could be determined, was absent and a tendency toward regeneration or healing of the lesion was observed. The roentgenogram made after healing showed a distinctive picture consisting of absence of the head and neck of the talus with a whorl of callus projecting upward from the distal end of the bone. At no time prior to the onset of the condition, nor during its onset or course, was there any evidence of ulceration or of a non-specific infection of the overlying skin and soft tissue. The lesion could not, therefore, be attributed to extension of a superficial infection to the underlying bone. Neither was there any extensive neurotrophic disturbance present, as evidenced by absence of trophic ulceration, muscular atrophy, and advanced bone absorption, although a stocking-like anesthesia of the skin was detected over the feet and lower portion of the legs. Case Reports Case 1: A white female, aged 34, with far advanced mixed leprosy, predominantly lepromatous, of fourteen years duration began having a prolonged series of lepra reactions in the early part of 1946. These required several periods of hospitalization and were characterized by a diurnal temperature reaching 38.4° C., swelling of the face and extremities, erythema nodosum, and neuritis.