A new technique of low-frequency modulated electric current therapy, SCENAR therapy, was used in treatment of 103 patients with duodenal ulcer (DU). The influence of SCENAR therapy on the main clinical and functional indices of a DU relapse was studied. It was shown that SCENAR therapy, which influences disturbed mechanisms of adaptive regulation and self-regulation, led to positive changes in most of the parameters under study. Addition of SCENAR therapy to the complex conventional pharmacotherapy fastened ulcer healing, increased the effectiveness of Helicobacter pylori eradication, and improved the condition of the gastroduodenal mucosa.