Today controversial points of view in ulcer surgery are related to operative tactics. In principal resective and non-resective procedures and the type of anastomosis are discussed. Physiopathological criteria for decision are the effects on acid reduction, motility, intestinal acid exposure and entero-gastric reflux. Therapeutic security and the frequency of side effects are determined by these parameters. Postpyloric ulcer remains the domain of vagotomy. Gastric ulcers should be resected or treated by a combined procedure. In reconstructing the gastrointestinal tract the dualism of residual acid and postresectional reflux must be taken into account.