The discovery of Helicobacter pylori (H. pylori) provided a possibility to cure effectively patients with peptic ulcers. Recent studies have shown varying susceptibility of H. pylori strains to antibiotics and increasing resistance to some of the recommended drugs. The purpose of the present study was to evaluate the efficacy of the currently recommended eradication schemes and to assess the increasing resistance of H. pylori strains to recommended antibiotics. Furthermore, the effect of probiotics (Lacidofil) on the efficacy of first-line treatment with amoxicillin and clarithromycin was analyzed. The study population consisted of 641 patients: 192 received amoxicillin with clarithromycin and proton pump inhibitor (PPI), 241 - tetracycline, tinidazole, bismuth and PPI, 53 - amoxicillin with clarithromycin and PPI supplemented with Lacidofil. The efficacy of eradication treatment was evaluated by the (13)C-urease breath test. The microbiological examination included 111 samples of H. pylori. The present study demonstrated low efficacy of the tetracycline, tinidazole, bismuth and PPI scheme i.e. 71.4%, moderate efficacy of the amoxicillin with clarithromycin and PPI scheme i.e. 85.9%, whereas the supplementation with Lacidofil significantly increased the efficacy of eradication to 94.3%. The microbiological examination revealed a relatively high level of primary resistance to clarithromycin (22.2%) and a high level to metronidazole (46.7%), with no resistance to amoxicillin. However, the most important finding is the high level of secondary resistance to clarithromycin and metronidazole (more than 66% in both cases). The present findings suggest the need for modification of the recommended eradication schemes.