The present study evaluated the anti-Helicobacterpylori activity of Alchemilla glabra Neygenf. (A. sect. Alchemilla), A. monticola Opiz (A. sect. Plicatae S.E. Fröhner), A. fissa Günther & Schummel (A. sect. Calycinae (Buser) Buser) and A. viridiflora Rothm. (A. sect. Calycinae), and identified ellagic acid and quercetin-3-O-β-glucoside. Anti-H. pylori activity was tested against ten clinical isolates and one reference strain (ATCC 43504). The methanol extracts were more active than the dichloromethane and cyclohexane extracts. The ranges of concentrations were between 4 μg/mL for methanol extracts of A. viridiflora, A. glabra and A. monticola, and 256 μg/mL for cyclohexane extracts of A. viridiflora, A. glabra and A. fissa. The best overall activity was obtained with A. monticola extracts. No significant difference was found in the ellagic acid contents of the methanol extracts of the tested Alchemilla species (0.2-0.3 mg/mL), and anti-H. pylori activity was similar (4-32 μg/mL). Ellagic acid exhibited strong activity at very low concentrations (0.125-0.5 μg/mL), while the second identified compound, quercetin-3-O-β-D-glucoside, was also very active in concentration of 2-16 μg/mL.