Structure, activity and clinical use of Ginkgo biloba extract are described. Ginkgo biloba extract contains two important groups of chemical compounds: flavonoids and terpens. The effects of Ginkgo biloba extract concern vascular, rheological and metabolic processes. Several membrane mechanisms seem to be involved: protection of the ultrastructure against free radicals, modulation of some enzymatic systems and ionic pumps. Various mechanisms of action with clinical aspects are described in details. Preparations of Ginltgo biloba are used in many medical branches. They are safe and well tolerated.