Anticoagulation therapy may be complicated by spontaneous onset of an intramural hematoma of the duodenum and small intestine. Other causes were published only as case reviews. Radiological literature describes typical findings, which are fundamental for the diagnostics. However, only a fraction of patients present with them. This article describes a case of a female patient, treated for stomach pains. Based on her history, laboratory findings, ultrasound and CT findings, the condition was mistaken for acute pancreatitis and the pancreatic body necrosis with pseudocysts, drained under the CT control. The correct diagnosis was established a year later. Surgical revision indicated for a cystoid relaps and difficulties with intestinal passage revealed an old intramural hematoma within the duodenojejunal junction wall, the hematoma was evacuated and gastroenteroanastomosis performed.