History and Clinical Findings: A 42-year-old woman was admitted with blood pressure crisis. She complained of frontal headache. On clinical examination, a I stenotic noise was found localized to the epigastrium. Some days earlier, a pancreatic ''tumor" had been diagnosed sonographically by her general practitioner. Investigations: At B-mode sonography, a sharply delineated lesion at the pancreatic tail was found. With color Doppler sonography, blood flow could be detected within the "mass", which was interpreted as an aneurysm of the superior mesenteric artery. Furthermore, an aneurysmatic gastroduodenal artery was diagnosed. The sonographic findings were confirmed by CT scan, which additionally revealed an aneurysm of a segmental renal artery. Course: Given the danger of spontaneous rupture, the aneurysm of the superior mesenteric artery was resected. Under antihypertensive therapy, normal blood pressure values could be achieved, and the patient is symptom-free. Conclusion: Color and power Doppler sonography are useful in the differential diagnosis of pancreatic tumors. With these methods, erroneously suspected "tumors", e.g., an aneurysm of a mesenteric artery, can be differentiated from true lesions. Thus, complications of the aneurysm such as spontaneously rupture or intervention-associated bleeding can be prevented.