The bacterium Helicobacter pylori is recognized as the main causal agent of active chronic gastritis and peptic ulcer. For many years, traditional medicine has made use of several plants for the treatment of these afflictions; nevertheless, their possible effect upon the bacterium has just begun to be investigated. This study summarizes and analyzes the studies, conducted up to date, of plants with anti-H. pylori activity. It is proposed that their action on H. pylori is mainly directed to the depletion of bacterial population rather than to its eradication, as the current anti-ulcer therapy does. Plant species are presented as a very diverse source of bactericidal compounds, as well as for the development of new therapies for H. pylori control.