Due to its chemical structure, low cost and large-scale production, lactose is a promising source for the production of nutritive sweeteners or sugar alcohols. Lactose is converted into lactitol through a set of chemical reactions known as catalytic hydrogenation. Although lactitol is the predominant product, there is a considerable formation of lactulitol, lactobionic acid, sorbitol, and galactitol. These subproducts are formed through a combination of isomerization, hydrolysis, oxidation, and hydrogenolysis. Reaction products are strongly dependent on the reaction conditions and catalyst type. This presentation will summarize our laboratory efforts and elsewhere in understanding reaction kinetics of catalytic hydrogenation of lactose. We studied the effects of temperature (90–150°C) and pressure (40–150 bar) on lactitol selectivity using 5% Ru/C as a catalyst system. Experimentation utilized a laboratory scale high-pressure reactor with custom fabricated catalyst basket. Such configuration allows the catalytic hydrogenation of lactose to be controlled by intrinsic kinetics rather than diffusion and mass transfer. Preliminary data followed the Langmuir–Hinshelwood–Hougen–Watson kinetics under the assumption of surface reaction as rate-determining step. We have developed a mathematical model to describe the influence of temperature and pressure on the reaction rate based on the Arrhenius and Eyring theory. The activation energy for lactitol formation was 73.54 ± 6.71 kJ mol⁻¹, while the activation volume was 57.25 ± 11.2 cm³ mol⁻¹. Research in this area is not as advanced as enzymatic catalysis, and there are opportunities for further studies in the field of reaction optimization, detailed characterization of products and their properties, and system scale up.