To verify the effect of age on gastric secretions in gastric (GU) and duodenal ulcer (DU) patients, we carried out a retrospective study evaluating basal and stimulated gastric acid secretion in 427 peptic ulcer subjects aged between 12 and 73 years (GU = 74, DU = 353) in addition to studying gastric juice pepsin, serum pepsinogen group A (PGA) and gastrin in 175 patients (GU = 28, DU = 147). All subjects were then divided into groups according to their sex and age (< 30, 30-39, 40-49, 50-59 and > 60 years). Basal, maximal and peak acid outputs (BAO, MAO, PAO) were unchanged in the various age groups, though MAO and PAO were higher in males than females and in DU than in those with GU, even in the elderly (> 60 years). Pepsin and gastrin levels were unchanged at the various ages in GU and DU, while PGA was higher in males with DU aged 50 or over. This demonstrates that acid, pepsin and gastrin secretions do not change with age in ulcer patients. Acid secretion retains its typical distribution according to pathology (DU > GU) and sex (males > females), and also appears to have a fundamental pathogenetic role in peptic ulcer in the elderly.