Non-traumatic intramural duodenal hematoma (IDH) with duodenal obstruction caused by acute pancreatitis is rare. Most patients with non-extensive hematoma show improvement with non-operative treatments. Percutaneous drainage or surgery may be necessary in cases with suspected malignancy, perforation, or intestinal tract obstruction. We present a case of IDH caused by acute pancreatitis that led to obstruction of the duodenum and an experience of successful endoscopic decompression of the hematoma.