General trends and specific features of the reaction of dicyclopentadiene (tricyclo[5.2.1.0(2.6)]decadiene-3,8) hydrogenation to dicyclopentene (tricycle[5.2.1.0(2.6)]decene-3) with hydrogen in the liquid phase under mild conditions at atmospheric pressure over a finely divided 1% Pd/C catalyst have been studied. The kinetic parameters that characterize the effect of the solvent nature, catalyst concentration, and temperature on the rate of hydrogen uptake in the hydrogenation process have been determined. To substantiate the conclusion of the sequence of saturation of the dicyclopentadiene double bonds in terms of the mechanism of heterogeneous catalysis, their reactivity has been compared. It has been shown that in the presence of a number of functionalized aromatic compounds as a stabilizing additive, the yield of desired dicyclopentene increases to 98.5-99 mol % with the complete conversion of dicyclopentadiene. The structure of dicyclopentadiene and its hydrogenation product dicyclopentene has been confirmed using spectroscopic methods.