Calcific myonecrosis is a rare and late sequela of compartment syndrome, which becomes symptomatic years after the initial trauma. We diagnosed this condition in a 64-year old man, 42 years after he sustained a shot-gun wound to the right lower leg. Total excision of a peripherally calcified, cystic mass, continuous with the anterior tibial muscle belly resulted in complete resolution of symptoms. Consideration of the diagnosis is warranted in patients with a history of major injury who develop a soft tissue mass in the traumatized compartment. The treatment of choice is marginal excision.