PURPOSE: To determine the plain film findings of acute neuropathic joint in diabetic foot. MATERIALS AND METHODS: Acute neuropathic joint in diabetic foot was considered when fragmentation of the articular ends of bone and subluxation of the affected joint developed within eight weeks after clinical onset of diabetic gangrene. Eight toes of six diabetics were satisfactory to our criteria. We analyzed plain radiographic findings of the affected joint and soft tissue, interval changes in follow-up radiographs, and deformities after healing. RESULTS: The time interval between clinical onset of gangrene and bone destruction ranged from 2 weeks to 4 weeks(mean 2.6 weeks). Plain radiographs showed fragmentation of the articular ends, subluxation, and soft tissue swelling of the metatarsophalangeal joint or interphalangeal joint. The significant feature of these patients was rapid progression of the lesions. Clinically, all patients had diabetic gangrene in affected toes, however, there was no evidence of osteomyelitis in our series. Amputation was done in 2 cases, and lesions in 3 of the remaining 4 cases were repaired spontaneously with regression of gangrene, leaving radiological residua such as pointed-end, tapered-end, and ball and socket deformity. CONCLUSION: Rapid disorganization of the joint with associated evidence of soft tissue gangrene in plain radiograph is believed to be valuable for the diagnosis of diabetic osteoarthropathy.