The influence of in situ generated ultrafine molybdenum disulfide particles on the dispersion properties of feedstock and the acidity of a microspherical zeolite catalyst during the catalytic cracking of a vacuum distillate has been studied. The character of change in both the yield of catalytic cracking products and the hydrocarbon group composition of the gasoline fraction indicates that molybdenum disulfide exhibits hydrogenating activity under the catalytic cracking conditions. It has been shown that modification with molybdenum disulfide can result in a reduction in the yield of light gas oil, the olefin content in the gasoline fractions, and the yield of hydrogen and, in general, opens the possibility of controlling the qualitative and quantitative compositions of catalytic cracking products.