To evaluate how the introduction of H2-receptor antagonists has modified the epidemiology of surgical management of peptic ulcer, we examined data records of patients operated on for gastric or duodenal ulcer in our Institute. Patients were divided into two groups: a) patients operated from 1970 to 1979 and b) patients operated from 1980 to 1992. The comparison between the two groups showed the following variations: decrease in male/female ratio from 8 to 4.4:1 (p = 0.0009); decrease in duodenal/ gastric ulcer ratio from 5 to 3.5:1 (p = 0.02); decrease in elective/emergency surgery ratio from 16 to 6.4:1 (p = 0.00006); increase in mean age of patients undergoing emergency operations from 51 to 58 years (p = 0.05); decrease in elective/emergency surgery ratio for gastric ulcer from 17.5 to 5.3:1 (p = 0.03), above all for the increase in emergency operations for hemorrhage; decrease in the prevalence of operations for refractory duodenal ulcer from 49% to 36% (p = 0.00009). Our findings show that H2-receptor antagonists have greatly modified the epidemiology of surgical treatment of peptic ulcer with a clear decrease in elective surgery for refractory duodenal ulcer in men and an increase in emergency surgery for gastric ulcer.