The study of enzymatic transesterification of high oleic sunflower oil with butanol by immobilised Lipozyme(R) was realised in n-hexane and in a solvent-free system. A simplified model, based on the Ping Pong Bi Bi with alcohol competitive inhibition mechanism, was proposed to describe transesterification kinetics, The solvent-free reaction medium was characterised by higher initial velocities and a 6-times volumic productivity but at the thermodynamic equilibrium only about 60% of the potential oleic acid is converted into ester, against 95% in n-hexane. The resulting product is a mixture of ester, monoglyceride, diglyceride and triglyceride with lubricant and surfactant properties and its composition depends on the initial substrate ratio.