BACKGROUND In the present study we evaluated gastrointestinal motility after gastrectomy of a new pylorus-preserving technique that is becoming a popular operation for early stage carcinoma of the stomach. METHODS Using strain-gauge force transducers we studied gastrointestinal motility in control dogs, dogs after pylorus-preserving gastrectomy, and dogs after conventional distal gastrectomy with Billroth I reconstruction. Dogs with gastrectomy were reoperated upon after recording motility patterns, and the effect of vagal denervation of the gastric remnant on motility was investigated. Overall motility pattern, length of the digestive phase in the jejunum, and interval of the interdigestive phase III contractions were studied and compared among the three groups. RESULTS In dogs after gastrectomy without vagal denervation, the regular occurrence of interdigestive phase III contractions from the gastric remnant to the jejunum was identified. In dogs after gastrectomy with vagal denervation, however, no apparent interdigestive phase III contractions were observed in the gastric remnant. The duration of the digestive phase in the jejunum, which correlates with postprandial gastric emptying, was not different between the control dogs and the dogs having pylorus-preserving gastrectomy. However, this duration was significantly shorter in dogs having conventional distal gastrectomy compared with the control dogs, not only before but after vagal denervation. CONCLUSIONS These results indicate that the postoperative motor function after pylorus-preserving gastrectomy may be superior to that after conventional distal gastrectomy with Billroth I reconstruction.