This paper describes a patient who had the unusual association of idiopathic hypertrophic subaortic stenosis with a post-antrectomy dumping syndrome. Angina pectoris occurs when the patient is having dumping only. Hemodynamic correlates and actual objective demonstration of increase of murmur, decrease of stroke volume, and decrease of pulse pressure during a test meal are presented as evidence that the pain is secondary to outflow obstruction. The mechanisms of angina pectoris in outflow tract obstruction are discussed and related to this patient who also demonstrated severe segmental coronary disease on coronary cineangiography but in whom pain did not occur with exertion.