The data on use of the GKD-205 and GKD-300 catalyst system in the L-24/7 unit are generalized. These catalysts lose activity during each regeneration, which negatively affects the unit's operating conditions. In refining diesel fuel of environmental class 2 (Euro-2), the output in feedstock decreases sharply and the temperature in the reactor increases. In addition, they are characterized by low mechanical strength: losses from wear are greater than 10 wt. %. It is recommended that they be replaced by highly effective catalysts with improved operating properties.