Background and aims: The success of Helicobacter pylori eradication using triple eradication therapy declines over time. In this prospective study, we have compared a group of naive H. pylori-positive patients receiving sequential therapy with our previously published naive H. pylori-positive control group who received ranitidine bismuth citrate -clarithromycin-amoxicillin eradication treatment. Moreover, the eradication success of these two treatment protocols was compared with that of recent standard triple eradication treatment results for the naive patients in our country and western communities. Methods: We performed invasive tests for H. pylori in naive patients who underwent gastroduodenoscopy in the Endoscopy Unit, Ankara University, Faculty of Medicine, and patients who were diagnosed as H. pylori-positive by these tests were rechecked by the same invasive tests one month after the completion of eradication treatment. The group receiving sequential therapy was given pantoprazole + amoxicillin during the first seven days and pantoprazole + metronidazole + tetracycline during the second seven days. These patients were compared with the H. pylori-positive naive control group patients, who were given ranitidine bismuth citrate + clarithromycin + amoxicillin. The patients in whom eradication was achieved in the 4th week with sequential therapy were reevaluated one year later regarding the success of eradication with the H. pylori stool antigen test. Results: The average age of the 108 patients who received the sequential therapy was 45.2 +/- 12.5 years. The average age of the 75 patients who received ranitidine bismuth citrate treatment was 41.2 +/- 12.6 years. Six (5%) patients in the consecutive treatment group developed deterioration in taste in the mouth and 10 (9%) developed diarrhea. However, no side effects severe enough to require discontinuation of the treatments were observed in either treatment group. The results of the invasive tests were evaluated by the end of the first month, and revealed an eradication rate of 88% in the sequential treatment group versus 95% in the ranitidine bismuth citrate treatment group. Sixty-eight of 94 patients in whom eradication was achieved by sequential therapy were reevaluated with H. pylori stool antigen test in one year, and eradication was found to persist in 52 (77%) of these 68 patients. Conclusions: High rates of eradication were achieved in both groups in the 4(th) week evaluation. It was observed at the follow-up performed one year later that the eradication achieved with sequential therapy persisted in 77% of the patients treated.