Pylorus-preserving pancreaticoduodenectomy (PpPD) has been performed increasingly for periampullary tumors as a modification of conventional pancreaticoduodenectomy (PD) with antrectomy. Five randomized controlled trials (RCTs) and two meta-analyses have been performed to compare PD with PpPD. The results of these trials have shown that the two procedures were equally effective concerning morbidity, mortality, quality of life (QOL), and survival, although the length of surgery and blood loss were significantly lower for PpPD than for PD in one RCT and in the two meta-analyses. Delayed gastric emptying (DGE) is the major postoperative complication after PpPD. One of the pathogeneses of DGE after PpPD is thought to be denervation or devascularization around the pyloric ring. Therefore, one RCT was performed to compare PpPD with pylorus-resecting pancreaticoduodenectomy (PrPD; a new PD surgical procedure that resects only the pyloric ring and preserves nearly all of the stomach), concerning the incidence of DGE. The results clarified that the incidence of DGE was 4.5% after PrPD and 17.2% after PpPD, which was a significant difference. Several RCTs of surgical or postoperative management techniques have been performed to reduce the incidence of DGE. One RCT for surgical techniques clarified that the antecolic route for duodenojejunostomy significantly reduced the incidence of DGE compared with the retrocolic route. Two RCTs examining postoperative management showed that the administration of erythromycin after PpPD reduced the incidence of DGE.