Ethanol-induced alterations in the lipid composition of Saccharomyces cerevisiae grown in the presence of exogenous fatty acids were studied. The addition of both palmitic acid and ethanol (4-8%) to the basal medium resulted in a striking increase in the palmitic acid content and decreases in the content of myristoleic, palmitoleic, and oleic acids in the phospholipid fatty acid composition, compared with their contents in the absence of ethanol, On the other hand, the addition of linoleic acid to the medium containing ethanol (4-8 %) resulted in an increase in oleic acid and corresponding decreases in myristoleic, palmitoleic acid, and palmitic acid, while the linoleic acid levels were maintained in excess of 14%, Generally, growth in the presence of ethanol resulted in a reduction in the amount of phosphatidylcholine (PC) and more obviously, in the amount of phosphatidylethanolamine (PE), leading to an increase in the PC/PE ratio, A good cell survival rate in replacement cultures containing 18% ethanol was attained when cells were preincubated in the presence of ethanol (4-8%). Under the same conditions, palmitic acid-enriched cells had additional ethanol-endurability and a higher cell-membrane integrity than linoleic acid-enriched cells.