The total fatty acids of cultured cells from 11 cell lines (nine species of plants) were determined. Linoleic acid was the most abundant fatty acid in most of the cultures (16.3%–60.9%, average = 39.4%). Palmitic acid varied from 19.1% to 54.8%, average = 28.4%. Stearic and oleic acids were usually less than 10%, with averages of 7.4% and 4.7% respectively. Linolenic acid varied from 3.5% to 19.8% in nine of the cell lines but morning glory (Ipomoea sp.) and soybean (Glycine max) contained 35.7% and 51.2% respectively. Arachidic acid was either absent or present in amounts of less than 5%.The total fatty acid patterns of various parts of Ipomoea sp. and Glycine max plants were compared with those of the cultured plant cells. The fatty acid composition of the leaves and of the cultured cells were quite similar in both plants. The lipids found in tissue culture cells are not necessarily comparable to those of the part of the intact plant from which the cell culture was established.