Ginkgo biloba is one of the oldest, still existing plants. Extracts from its leaves were already used in ancient China whereas in the Western World, they have been utilized only since the Sixties when it became technically possible and feasible to isolate the essential substances of Ginkgo biloba. Pharmacologically, there are two groups of substances which are of some significance: the flavonoids, effective as oxygen-free radical scavengers, and the terpenes (i.e. the ginkgolides) with their highly specific action as platelet activating factor (PAF) inhibitors. Clinically important indications for Ginkgo biloba extracts are cerebral insufficiency and atherosclerotic disease of peripheral arteries of intermediate severity. In several placebo-controlled clinical studies, symptoms of cerebral insufficiency have been effectively and significantly influenced. Most of these investigations have examined the efficacy of Ginkgo biloba extracts such as EGb 761 and LI 1370.