Micromethods are described for rapid quantitative lipid analysis of human liver specimens obtained by percutaneous needle biopsy. Total phospholipid, free fatty acids, triacylglycerol and free and esterified cholesterol were separated by thin layer chromatography and, with the aid of an internal standard, quantitated by specific chemical assays. Individual phospholipids were also separated and quantitated. Fatty acid esters were transmethylated and assayed by gas-liquid chromatography. The results of recovery and reproducibility experiments and lipid values for normal human liver are reported. These methods provide a new approach for investigating the pathogenesis of liver disease and may well prove useful in analysing lipids from biopsies of other tissues.