Content of prostaglandins A, E and F, activity of prostaglandin synthetases, content of fatty acids in the phospholipid fraction were studied in liver tissue of rats exhibiting preference for water or ethanol. In the animals with marked preference for ethanol synthesis of prostaglandins E2 and F2 alpha, content of the prostaglandins F were distinctly higher. Content of prostaglandins E was increased in the rats exhibiting preference for water. Content of myristate and linoleate was higher and that of stearate was lower in liver tissue phospholipids of ethanol-consuming rats as compared with the animals preferring water. Possible role of prostaglandins in development of various metabolic pools in rats exhibiting various preference for ethanol is discussed.