In the ulcer pyloroduodenal stenosis the stages of complete and noncomplete decompensation are suggested. In 73% of observations, while performing an adequate preoperative preparation it was possible to convert pyloroduodenal stenosis from the stage of complete decompensation into the stage of noncomplete decompensation, in which the performance of organpreserving operation is possible. In the patients, suffering pyloroduodenal stenosis in the stage of noncomlete decompensation, resection of 2/3 of stomach is performed.