AbstractSeveral groups of antagonists of platelet‐activating factor (PAF) are reviewed. The characteristics of PAF binding sites on mammalian cell membranes are described together with the activities of non‐specific and synthetic PAF‐antagonists. The specificity of the ginkgolides to bind to PAF‐receptors is discussed and the effects of these natural products in a range of biological systems is emphasized. Other groups of natural PAF‐antagonists described are the lignans and gliotoxin related compounds. The structural chemistry, structure‐activity relationships and pharmacological properties of these drugs are compared to the