Effective eradication regimes of Helicobacter pylori infections are nowadays based on administration of a substance with a strong suppressive effect on production of gastric HCl combined with two antibiotics. As suppressor of gastric HCl production unequivocally some drug from the group of proton pump blockers is used. As to antibiotics, in first line therapy the following are recommended: clarithromycin, amoxicillin, metronidazole. A problem in the eradication therapy of Helicobacter pylori infection in recent years is the increasing resistance to clarithromycin and apparently also metronidazole. In the Czech Republic the resistance to clarithromycin in relation to Helicobacter pylori is stabilized at a level lower than 3.0 %. Resistance to metronidazole was reported in 1992 within the range of 24 % - 26 %, however in 2001 it was already 36.0 %. Therefore the question arises whether it is possible under our conditions to check the increasing metronidazole resistance by a drug which by its spectrum of action resembles metronidazole while it differs from it as to its chemical structure. This is the reason why the authors implemented a trial where metronidazole was replaced by tinodazole (Avrazor, Léciva Co.). The results revealed that in the group treated with tinidazole eradication was achieved after 7-day administration of ornidazole in 93.0 %, in the group where part of the eradication regime was metronidazole eradication was 82.6 %. The tolerance of both drugs was very good. The authors recommend to include the pattern omeprazole 2 x 20 mg, clarithromycin 2 x 500 mg and tinidazole 2 x 500 mg among first line therapeutic regimes.