Gastric emptying of liquids and solids was evaluated in ten dogs with gastric fistula before and after either truncal vagotomy, antrectomy, or pyloroplasty. In subsequent operations, the vagotomy group underwent either antrectomy or pyloroplasty, and the antrectomy and pyloroplasty groups were vagotomized. Vagotomy significantly inhibited the emptying of both liquids and solids (p less than 0.001) when the pyloric antrum was intact. When the antropyloric mechanism was removed by antrectomy, the effect of vagotomy was to accelerate the emptying of liquids (p less than 0.05) but to impair the emptying of solids (p less than 0.001). When the pylorus was destroyed by pyloroplasty, vagotomy markedly accelerated the emptying of liquids but had little effect on the emptying of solids. Neither antrectomy nor pyloroplasty had any significant effect on the emptying of solids. Pyloroplasty caused minor acceleration of emptying of liquids while antrectomy had no effect.