There is growing interest in using the derivatives of iso- and anteiso- methyl-branched fatty acids in lubricants and industrial fluids to replace petroleum-based products, and others at Iowa State University are exploring the expression of these branched fatty acids in oil seeds. The branched acids have the advantages of being biodegradable, and stable to oxidation. Branched fatty acids and their derivatives have lower melting points than their straight-chain counterparts. Thus, they perform better at low temperatures, but physical property data for branched acids and esters is limited. In this study, a complex mixture of branched methyl esters was obtained from lanolin through saponification, extraction of unsaponifiables with heptane and methylation. Hydroxy compounds were removed by chromatography on alumina. Vacuum spinning-band distillation separated the mixture roughly by chain length. Counter-current urea complex formation, and crystallization separated individual methyl esters. Pure (>95%) iso- methyl isomers with even chains 14, 16 and 18, and anteiso- methyl isomers with odd chain 15 and 17, were obtained. Transesterification was used to convert methyl esters to isopropyl esters. The melting point and heat of melting of each ester were determined by differential scanning calorimetry. Nuclear magnetic resonance was used to verify the structure of branched esters. The ease of forming urea complexes was: normal C[subscript n+1] > normal C[subscript n] > normal C[subscript n-1] > iso C[subscript n] > unsaturated C[subscript n]> anteiso C[subscript n-1] (where n is a particular chain length).