The studies on the enzymatic restructuring process, with the application of interesterification of the fat mixtures, containing fatty acids of omega-3 group (mono-, di-, tri-, tetra-, penta- and hexaenoic) with a differentiated chain length and degree of saturation, were carried out. The investigations were conducted in a model system, in laboratory scale. The Lipozyme® RM IM of Novozymes® A/S company, Denmark, revealing specificity to the sn-1,3 triacylglycerol (TAG), was used as a biocatalyst. The research material consisted of rapeseed oil and fish oil with different levels of EPA and DHA acids. The enzymatic processes of interesterification were conducted in batch system with a stirrer and without solvent. The optimal parameters of the process were determined and the analysis of the obtained product was carried out.