The aim of this study of 225 duodenal ulcer patients was to determine the association of cigarette smoking to ulcer recurrence. In this study, smokers were mostly men whose smoking habit was positively associated with a past history of duodenal ulcer, stress and alcohol consumption. These characteristics are regarded to favor ulcer recurrence. In 161 patients not on maintenance therapy, smokers had a higher recurrence rate than nonsmokers, even when foregoing patients characteristics were taken into consideration. No difference in recurrence rates could be observed between nonsmokers and smokers in 64 patients under maintenance therapy. In conclusion, our findings suggest that smoking plays a major role on recurrence of duodenal ulcer and that maintenance therapy can overcome the adverse effect of cigarette smoking on ulcer recurrence.