The effects of alcohol on the formation of prostaglandins (PGs) and the blockade of some actions of alcohol by PG-inhibitors suggest that PGs may be involved in the action of ethyl alcohol. Regulation of lipid peroxidation and synthesis and release of precursor fatty acids may affect the overall formation of PGs. The effect of alcohol may be qualitative for several reasons: (i) the possible preferred formation of 1-series of PGs would mean an important qualitative change in PG-impact in some tissues; (ii) inhibition of PG-metabolism in the lung might affect mostly the plasma levels of PGE; (iii) a selective blockade of certain PG-effects and a potentiation of some others gives rise to qualitative changes in the actions of PGs. PGs may be involved in several acute or short-term reactions caused by alcohol. Chlorpropamide-alcohol flush, alcohol intolerance and hangover are effectively alleviated by a prophylactic use of PG-inhibitors. Speculatively PGs might also be involved in migraine attacks provoked by alcohol and in antabuse in reaction. The roles of PGs in the regulation of vascular tone, water and electrolyte balance as well as in certain secretory and metabolic processes may be important in the generation of alcohol related reactions.