There are suggestions, that the idiopathic non-ulcer dyspepsia is related to the chronic gastritis type B coexisting with C. pylori infection. Presented studies were aimed at the assessing of an effect of the treatment with De-Nol on the course of the idiopathic non-ulcer dyspepsia of C. pylori infection. Gastroscopic examination was performed in 52 patients with non-ulcer dyspepsia before and after the treatment with De-Nol administered for 4-8 weeks. Campylobacter pylori was isolated from 71% of patients with idiopathic non-ulcer dyspepsia. An infection was eradicated in 97.4% of patients treated with De-Nol. The number of dyspeptic episodes decreased in by 96% of patients, including 33% of patients in whom total recovery was noted. De-Nol was well tolerated. De-Nol is highly effective in the eradication of C. pylori and produces clinical improvement in the majority of patients with non-ulcer dyspepsia.