A review was conducted of the operations of highly selective vagotomy (HSV) and truncal vagotomy and pyloroplasty (TVP) performed for peptic ulcer disease. Gastric acid output was reduced equally after both procedures: basal acid output was reduced by 80% and maximal acid output by 50% to 60%. Not surprisingly, therefore, the recurrence rates were similar (6.6% after HSV compared to 5.6% after TVP). However, the mortality following HSV was 0% compared with 0.7% after TVP. The incidence of all side effects was lower following HSV, so that the results in 86% of patients who underwent this operation were considered excellent or very good (Visick grades I and II). The authors conclude that HSV should be considered the primary conservative procedure in the surgical management of peptic ulcer disease.