WERNICKE-KORSAKOFF encephalopathy is a serious neurological syndrome caused by thiamine deficiency and characterized by ataxia, ophthalmoplegia, nystagmus, and mental confusion.1 Although this syndrome is common in alcoholics, it may occur in a number of other circumstances, including gastric carcinoma, pyloric obstruction,2 hyperemesis gravidarum,1 and prolonged intravenous (IV) hyperalimentation.3 We report two cases of Wernicke-Korsakoff encephalopathy as a previously unrecognized complication of gastric plication for the treatment of morbid obesity. Both patients were young women, two to four months after gastric plication, and had protracted vomiting after surgery without vitamin supplementation. Report of Cases Case 1.— A 33-year-old woman weighing 130 kg was admitted to a community hospital for a gastric plication for morbid obesity on July 31, 1980. She tolerated the procedure well and was discharged on a postgastrectomy diet. She required two hospitalizations during the ten weeks after plication for persistent nausea and vomiting. She