High-velocity gunshot injury (muzzle velocity greater than 609.6 m/s) is uncommon and primarily a military injury. Humerus shaft fracture, caused by a high-velocity gunshot, should be considered as a severe open fracture. The principles of treatment are immediate and aggressive irrigation, wide debridement, primary delayed wound closure, and broad-spectrum intravenous antibiotics. External fixation has been widely used for fracture fixation. We report a case of humerus shaft fracture secondary to high-velocity gunshot (machine gun) injury, with a literature review.