We have obtained improved qualitative and quantitative information about plasma lipid composition by adopting capillary gas-liquid chromatography to the determination of plasma total lipid profiles. The new procedure takes advantage of the good recoveries of high molecular weight solutes provided by short capillary columns as well as of the absence of sample fractionation during on-column injection. The major improvements in the gas-liquid chromatographic determination of plasma lipid profiles are the greatly increased carbon number resolution of the solutes and the minimal sample size requirements on the capillary columns. In many instances there is a partial resolution of the saturated and unsaturated molecules within a carbon number, which provides clues to the fatty acid composition of the molecular species. In other respects the new plasma total lipid profiles are similar to those obtained on packed columns. The plasma lipids are dephosphorylated by phospholipase C and trimethylsilylated before analysis.