Case histories of three young women who suffered small bowel infarction associated with oral contraceptives and progestational agents are presented. Two infarctions were due to superior mesenteric artery thrombosis and one to superior mesenteric vein thrombosis. All of these patients were of blood group A and smokers, factors which are known to predispose to vascular thrombosis. A study was made of 18 additional cases reported in the literature. It was found that many of these cases presented with a history of symptoms of 2 weeks of more and at operation some of the cases appeared to be reversible. One case was reported where apparent reversion of the process of vascular thrombosis occurred after cessation of the oral contraceptive.