Background: Helicobacter pylori, which infects at least half of the human population, is an etiopathogenetic factor in the development of chronic gastritis (CG), gastric and duodenal ulcer disease (UD), and is also considered a risk factor in the occurrence of some forms of stomach cancer. Various surface structures of H. pylori are important pathogenic factors. Methods: Reference (NCTC 11637, NCTC 11639) and freshly isolated H. pylori strains as well as samples of the gastric mucosa were examined using transmission (TEM) and scanning electron microscopy (SEM) by means of “JEM-100 В” (JEOL, Japan) and “Quanta 200 3D” (FEI Company, USA) systems, respectively. Samples for SEM fixed with formalin and not subjected to dehydration were sprayed with an electrically conductive layer of gold. Samples for TEM were prepared using negative contrast (NC) with ammonium molybdate and ultrathin sections (US) contrasted by Reynolds; fixation by Ito-Karnovsky was used in both cases. Accelerating voltage at TEM and SEM was 80 and 10 kV, respectively. Results: Three types of H. pylori surface structures were found: flagella, fimbria, and vesicles. Flagella were found both in the material of cultures maintained in vitro and in each native sample of the gastric mucosa. SEM images suggest the involvement of flagella in biofilm formation. On longitudinal sections of the flagellum, the outer electron-dense layer and the inner content in the form of a filament were visualized; on cross sections, the flagellum looked like an annular structure with a centrally located point accumulation of electron-dense matter. Paradoxically, the H. pylori forms with a defective cell wall also possessed flagella. Freely located flagellar sheaths without central filament were often found in vitro only. Fimbriae were found exclusively in negatively contrasted pure bacterial cultures material. In addition, vesicles detaching from the surface of bacterial cells were found both in the material of aging H. pylori pure cultures and in native samples of the gastric mucosa under CG and UD. A small part of the vesicles retains their connection with the cell wall, while detached vesicles are present in excess in the surrounding space. Massive detachment of vesicles leads to the formation of spheroplasts, devoid of an outer membrane. Conclusion: H. pylori has a representative set of surface structures that play an important role in the onset and development of the infectious process in the gastroduodenal area.