This multicenter, prospective, randomized, open, long-term study compares sucralfate (2 g daily) with ranitidine (150 mg daily) and no treatment in gastric ulcer (GU). We report the results of the second year of a scheduled 3-year follow-up, the outcome of the 1 st year has been reported earlier. The 24-month follow-up was completed by 142 patients who were continuously either treated with the drug randomly assigned at the beginning of the study or left untreated (i.e. 32 patients took 150 mg ranitidine at bedtime, 29 took 1 g sucralfate twice daily and 81 were left untreated, 23 of whom came from the ranitidine group, 19 from the sucralfate group and 39 from the untreated group). Seven patients dropped out and 26 subjects relapsed (5 under ranitidine, 4 under sucralfate and 17 untreated cases). Ranitidine versus previous ranitidine, sucralfate versus previous sucralfate and each one versus no treatment showed comparable relapse rates. An additional study, using Cox's models, showed that three variables have a significant correlation with relapse during the 1 st year of follow-up: therapy carried out (p = 0.0025), symptoms (p = 0.0047) and family history of ulcer (p = 0.0392). In conclusion, both ranitidine 150 mg and sucralfate 2 g proved effective in reducing GU relapse as compared with no treatment, an effect which does not seem to persist during the 2nd year of therapy, when the 'no treatment' option may be taken into account.