The scanty literature on distal tibiofibular synostosis includes descriptions of relatively few specific complaints. Here we report a case of a 24-year-old young soldier who sustained a left ankle lateral malleolar fracture about 6 months ago and was initially treated by the open reduction and internal fixation with plate & screw. But 6 months later, he suffered from an vague ankle pain, each time the symptoms occurred right after an active ambulation, ankle dorsiflexion, especially when he had exercised aggressively. The radiographs revealed that there was a mature distal tibiofibular synostosis. We treated the patient with surgical excision of synostosis. Post-operative condition was satisfied to all concern and the result was found to be excellent during one-year follow-up.