Purose: To discribe the radiologic findings of idiopathic portal hypertension and to find the points of differentiation between idiopathic portal hypertension and liver cirrhosis. Material and Mathods: Four portograms in five patients who for four years had suffered from pathologically confirmed idiopathic portal hypertension were retrospectively analyzed and compared with a portogram obtained from a cntrol subject with liver cirrhosis. Results: Portographic findings of idiopathic portal hypertension were paucity of medium-sized portal branches, irregular and obtuse-angled division of peripheral branches, abrupt interruption and an avascular area beneath the liver margin. Conclusion: A portogram of idiopathic portal hypertension may be useful in differentiating this andliver cirrhosis.