A method for the confirmation of the tranquilisers azaperone and its metabolite azaperol, of chlorpromazine, propionylpromazine and acepromazine, haloperidol, xylazine and the β-blocker carazolol in porcine and bovine kidney with LC-MS/MS was developed. Various solvents and extraction techniques and different ways of clean-up were tested and verified with incurred pig kidney from an animal study. The best extraction efficiency was reached by extraction with a mixture of ammonia in ethyl acetate and overhead shaking without SPE clean-up. The optimised method with a twofold sample extraction was validated according to Commission Decision 2002/657/EC in a matrix-comprehensive in-house validation supported by the InterVal software, taking into account the defined MRLs and recommended concentrations. The validated method can be used for residue control of the above-mentioned analytes in bovine and porcine kidney of food-producing animals in accordance with Council Directive 96/23/EC.