The antibacterial and antifungal activities of aqueous extracts obtained from aerial parts of Potentilla species: P. anserina, P. argentea, P. erecta, P. fruticosa, P. grandiflora, P. nepalensis var.'Miss Willmott', P. recta, P. rupestris and P. thuringiaca were investigated. The extracts showed the strongest antimicrobial activity against H. pylori (MIC=0.1/0.5 mg/ml).