Studies of the transesterification reaction of vegetable oils are important in the production of biodiesel. The rapeseed oil methyl ester concentration in the rapeseed oil layer was found to be directly proportional to RME yield in experimental conditions at the time interval to 180 minutes. The coherence is described by equation Y = 0.99147×C-2.690 (r = 0.961), where Y - stands for the RME yield, but C - for the RME content in oil layer. The increase of the molar ratio of methanol to oil (3.2-6.0 mol), the concentration of NaOH (0.2-1.5 weight % of oil) and the reaction temperature (from 30 to 80 °C), caused the increase of speed of the equilibrium entrance, and the yield of RME was increased about 8.0, 7.9 and 8.2% accordingly. For the implementation of batch processes, the preferred reaction temperature is 50 °C, the molar concentration of methanol is 4.0 mol and that of NaOH amounts to 0.5%. However, when using continuous processes, the reaction would be more efficient at higher temperature with lower quantities of catalyst and methanol.