Refinery wastes generated in conventional crude oil refining processes, or in accidental situations, are complex substrates for treatment and disposal. Petroleum desulphurisation catalysts can also be hazardous refinery waste. They contain various metals, such as cobalt, molybdenum, nickel and tungsten. In this paper, three petroleum refiner’s spent desulphurisation catalysts were investigated. These catalysts were not suitable for recycling and, therefore, were classified as hazardous waste. They were chemically characterised, including phase composition and their effect on a consortium of microorganisms used in the process of bioremediation. Catalysts contained up to 2.26 g kg−1 of total petroleum hydrocarbons, up to 56.7 g kg−1 of iron, 18.6 g kg−1 of molybdenum, and less than 0.1 mg kg−1 each of cobalt and nickel. These obtained results show that bioremediation of such waste is possible.