The kinetics of the chemo-enzymatic epoxidation of linseed oil is investigated. The multiphase process consists basically of a consecutive reaction a lipase catalyzed peracid formation followed by a Prilezhaev epoxidation. Kinetic measurements were carried out in an enzyme-recycle reactor. The kinetics of the process are incorporated in a semi-batch model and the rate constants of the involved reactions are determined by means of non-linear regression. Simulations with this mathematical model agree with the experimental data Found for the reaction system.