Histological distribution and in situ synthesis of lipids in young rabbit lens were studied with the employment of thin-layer and gas-liquid chromatographic techniques for the separation and characterization of lipids. The lens was found to contain lipids in every histological region with the highest concentration (61%) in the cortex. Fatty acids consisted almost exclusively of even-chain saturated and monounsaturated acids with only slight regional differences noted. The biosynthetic capacity of the lens was assessed by determining the incorporation of 1-[14C] sodium acetate into lenticular lipids. Radioactivity was detected in all of the lipids resolved by TLC with the highest uptake in PE, PC and cholesterol. A specific activity tained for the epithelium, cortex and nucleus, respectively, thelial region is the most metabolically active with respect to ratio of 1.0/0.5/0.05 was obtained for the epithelium, cortex and nucleus, which indicates that the epithelial region is the most metabolically active with respect to lipid synthesis.