The fatty acids composition of lipids in human adipose tissue and Japanese diet were analysed. It appeared that the fatty acid pattern of human adipose tissue resembled to that of fat in the weals. The total fatty acid composition of the adipose tissue of the patients with cholelithiasis, pregnancy, gastric disease and the normal showed a similar pattern. The percentage of stearic acid in phospholipid fraction of the adipose tissue, in the patients with cholelithiasis, lower than that of the other cases and normal subjects. No significant differences in the fatty acids composition were found between abdominal sub-cutaneous and perirenal adipose tissue.