Arterial pseudoaneurysm is a serious and potentially life-threatening late complication that can occur after gastrectomy or gastric resection for cancer. While this condition may occasionally be discovered during routine follow-up examinations, it more commonly presents as an upper gastrointestinal bleeding event. Unfortunately, the identification of a post-surgical arterial pseudoaneurysm is often underreported, making its recognition and management critical. Clinicians should maintain a high index of suspicion for this complication, especially in post-gastrectomy patients presenting with unexplained gastroduodenal bleeding or signs of hemorrhagic shock. Prompt diagnosis and intervention are essential as they can be life-saving in managing this rare but dangerous condition.