The authors present three patients with rectus sheath hematoma who were diagnosed with ultrasound and successfully operated upon. The importance of a correct preoperative diagnosis is stressed to avoid an unnecessary laparotomy. Ultrasound helps to localize the presence of an extra-abdominal mass located between the aponeurotic sheaths of the rectus muscle. Surgery is the best treatment since it is possible to evacuate the large hematoma, and at the same time it affords an opportunity to ligate the bleeding vessels, usually the epigastrics. No advantage is seen using conservative treatment, as several weeks may be necessary before complete resolution, while the patient is suffering considerable pain and discomfort.