Forty-eight out of six hundred and thirty patients with portal hypertension undergoing a celiac angiography series were diagnosed as cases of splenic artery aneurysm during the period 1977-1988. The case-control study of patients with portal hypertension with splenic artery aneurysms and those without was designed to characterize the angiological features. The splenic arterial flow was assessed by measuring the radii of the splenic arteries on celiac arteriograms. In the portal hypertensive patients with splenic artery aneurysms, the splenic artery was larger (p < 0.05) and the splenic arterial flow greater (p < 0.05), and these patients were in a more hyperkinetic state, than were those with no splenic artery aneurysm. The study suggests that splenic artery aneurysms in cases of portal hypertension may be the consequence of a hyperkinetic state in the spleen.