Although vascular injury after humeral fracture is very rare, it is a complication that has serious sequelae. It has been associated with proximal humeral fracture or shoulder dislocation in adults and humeral supracondylar fracture in children. However, delayed brachial artery occlusion after humeral shaft fracture has never been reported worldwide. Nevertheless, delayed brachial artery occlusion after humerus shaft fracture has the potential to cause serious complications in the short term as well as long term; therefore, it is essential to provide accurate diagnosis and prompt treatment. We report a case of delayed brachial artery occlusion after humeral shaft open fracture that was successfully treated with early diagnosis as well as effective treatment.