Among 128 patients with gastric and duodenal ulcer a diagnosis was made of Helicobacter pylori infections using the 14C-urea breath test (reference) as well as by a bacteriological test; from each patient the material for culture was obtained in two ways: Through gastroscopy-segments, and through an enterotest. It was shown that the diagnostic value of the enteroprobe in the detection of the Helicobacter pylori infection was relatively high in comparison with the results of the culture of the segments of the mucosa, especially for ulcers of the pyloric area and of the duodenum, whereas that value fell considerably for located in the cardia of the stomach. The entero-probe is thus recommended as a method of diagnosing Helicobacter pylori infections (using the bacterial material for culture and the antibiogram) but only for peptic ulcers of a selected location (pyloric area, duodenum).