Calcific myonecrosis (CM), a rare post-traumatic sequel of the lower limb, is characterized by calcified lesions. A diagnosis of CM can be difficult owing to the longtime span from the emergence of the original trauma to the onset of the symptoms of CM. This case report aimed to feature a case of a 55-year-old gentleman who presented with a progressive painful swelling in the anterolateral aspect of the right lower leg with the initial trauma arising 11 years ago. In the conservative treatment, a fluid-filled mass was formed. The histological examination of the biopsy suggested a diagnosis of CM. The patient underwent a complete debridement operation, after which vacuum sealing drainage was used to manage the space left. Three weeks later, direct wound closure was achieved. Five-year follow-ups showed an excellent outcome without recurrence. Complete surgical debridement combined with primary closure is recommended to manage CM.