Tall oil fatty acids are a second-generation bio-based feedstock finding application in the synthesis of polyurethane materials. The study reported tall oil fatty acids and their methyl esters epoxidation in a rotating packed bed reactor. The chemical structure of the synthesized epoxidized tall oil fatty acids and epoxidized tall oil fatty acids methyl ester were studied by Fourier-transform infrared spectroscopy. Average molecular weight and dispersity were determined from gel permeation chromatography data. The feasibility of multiple uses of the Amberlite® IRC120 H ion exchange resin as a catalyst was investigated. Gel permeation chromatography chromatograms of epoxidized tall oil fatty acids clearly demonstrated the formation of oligomers during the epoxidation reaction. The results showed that methylation of tall oil fatty acids allows obtaining an epoxidized product with higher relative conversion to oxirane and much smaller viscosity than neat tall oil fatty acids. Epoxidation in a rotating packed bed reactor simplified the process of separating the catalyst from the reaction mixture. The Amberlite® IRC120 H catalyst exhibited good stability in the tall oil fatty acids epoxidation reaction.