The feasibility of magnetic field was examined as a factor affecting sludge conditioning intensification. In the experiment sludge after preliminary anaerobic digestion was used, coming from a domestic wastewa-ter treatment plant. Digested sludge was taken directly from a fermentation tank. The experiment was run in three phases. They were performed on a laboratory scale, at various experimental stands. Different dosages of iron chloride, hydrogen peroxide and Fenton’s reagent were applied to determine their influence on the sludge properties as well as the effect of constant magnetic field on the conditioning parameters was deter-mined. Straight dependence was found between dosage of the reagents and the way of sludge introduction in the magnetic activity zone, as well as physical and chemical parameters of the prepared sludge.