(HP) colonization has any influence. Included in this study were 48 patients who underwent subtotal gastrectomy for a peptic ulcer (SGPU), 36 who underwent radical subtotal gastrectomy for gastric carcinoma (SGGC), 16 who underwent truncal vagotomy plus antrectomy (TV + AE), 24 with recurrent ulcer (RU) and 27 who underwent total gastrectomy (TG). The mean serum PGA levels in these five groups and in 40 healthy controls were 49.1 ± 30.4 ng/ml, 30.0 ± 14.8 ng/ml, 44.8 ± 21.7 ng/ml, 66.4 ± 42.8 ng/ml, 8.7 ± 3.0 ng/ml, and 94.7 ± 27.9 ng/ml, respectively. All patients except those with RU showed a diminished PGA level. The HP colonization rates of the patients who underwent partial resection were 45.8%, 22.2%, 50%, and 54.2%, respectively (P < 0.05). Age, gender, smoking, the type of gastroenterostomy, and underlying disease did not exert any influence on the measured PGA levels. However, higher PGA levels were observed in HP-colonized patients who either underwent SGPU or had RU. We conclude that various forms of distal gastrectomy, but not RU, elicit an indistinguishable acid secretory ability while HP colonization is responsible for the higher serum PGA levels in some patients following peptic ulcer surgery.