The physicochemical properties of liquid products from pyrolysis of wood biomass alone and its blend with residual fuel oil are compared. The characteristics of the liquid pyrolysis products with residual fuel oil in the mixed feedstock show a tendency to vary. Thermal conversion of combined sawdust and residual fuel oil in a 1:3 ratio provides the maximum yield and the best physicochemical properties of the liquid bioproduct. The possibility of utilizing the middle-distillate fractions of the pyrolysis products as diesel fuel components is examined.