Hardening of vegetable oils is reviewed from an engineering point of view. The present review focuses on kinetics of the hydrogenation and relevant transport and adsorption steps. It aims to contribute to accelerate new research to improve substantially on selectivities in general and a decrease of trans fatty acid content in particular. From a comprehensive literature review, we concluded the absence of reliable, mechanistically based kinetic rate expression, Moreover, transport limitations, both intraparticle and interfacial, cannot be excluded from the vast majority of available experimental data, Therefore, future research should focus on the development of intrinsic kinetic rate expressions, which may subsequently contribute to develop new and improved hydrogenation catalysts.