The co-processing of fossil and waste raw materials can postpone the depletion of fossil resources. The effect of wastecooking oil addition to catalytic vacuum hydrocrack residue was studied. Commercial NiW/SiO2–Al2O3, activated bentonite, Fe2O3 nanopowder, and synthesized CoMo/SiO2, CoMo/Al2O3 catalysts were used at 390 C and 15 MPa. The products were analyzed by simulated distillation (SimDis), C, H, N, and S elemental analysis, GC and solubility in nheptane The vacuum residue conversion decreased in the order CoMo/Al2O3[CoMo/SiO2 = NiW/SiO2–Al2O3 [bentonite = nano Fe2O3. CoMo/Al2O3 catalyst was selected for hydrocracking the vacuum residue and its mixture with waste cooking oil. The best yield of light compounds with the highest hydrogen content in the product occurred when 20 wt% of waste cooking oil and 80 wt% of vacuum residue were used. A bigger content of waste cooking oil generated an increase in the solid yield production (10 wt%). Co-processing produced lighter hydrocarbons and deoxygenation intermediates.