Rectus sheath hematoma (RSH) is a rare complication that usually occurs in patients receiving anticoagulation therapy. It can mimic an acute abdomen and be life-threatening. RSH can develop even with prophylactic dose of heparin. Early recognition is necessary to decrease morbidity and mortality. RSH should be considered in anticoagulated patients who develop sudden onset of abdominal pain. RSH is usually managed conservatively, but sometimes requires surgery. Patients who are taking antiplatelet require careful monitoring with the use of anticoagulation (AC). It is important to identify them early. This is a case of 69-year-old female who presented with epigastric pain secondary to rectus sheath hematoma. She was receiving subcutaneous injections of heparin for left lower quadrant pain and swelling for venous thromboembolism prophylaxis. Ultrasound of abdomen revealed large rectus sheath hematoma.