['The aim of the study was to evaluate the effect of smoking and drinking habits, in separate and joint analyses, on the efficacy of H. pylori eradication.', 'A total of 250 patients were recruited. They were treated with a 7-day course of omeprazole, amoxicillin, tinidazole (OAT), omeprazole amoxicillin, clarithromycin (OAC) or omeprazole, clarithromycin, tinidazole (OCT). The efficacy of H. pylori eradication was tested with a CLO-test and histology 4 weeks after the completion of antibacterial therapy.', 'Drinking was found not to affect the efficacy of H. pylori eradication in any therapeutic group, while smoking decreased it in the OAC group (smokers 69.6%, non-smokers 94.3%, p=0.006). In the OAT treated group H. pylori eradication rate was lower in smokers-non-drinkers than in smokers-drinkers and non-smokers-non-drinkers (38.9% vs 83.2% and 70.0%, p=0.002 and p=0.034, respectively), while in the OAC treated group, smokers-non-drinkers had lower eradication efficacy than non-smokers-drinkers and non-smokers-non-drinkers (59.1% vs 100% and 91.3%, p=0.01 and p=0.012, respectively). In the OCT treated group, differences between subgroups were not significant.'] Are smoking and drinking habits important predictors of Helicobacter pylori eradication?