The aim of the study was to determine the influence of increasing cobalt soil contamination (0 mg·kg−1, 20 mg·kg−1, 40 mg·kg−1, 80 mg·kg−1, 160 mg·kg−1, 320 mg·kg−1) after the application of neutralising substances on selected soil properties. In the soil without an addition of neutralising substances, the highest doses of cobalt caused the pH, total exchangeable bases, cation exchange capacity and the degree of base saturation to decrease and the hydrolytic acidity of soil to increase. Among the substances used, zeolite and calcium oxide (particularly) had the most advantageous influence on the analysed soil properties. They caused the pH, total exchangeable bases and cation exchange capacity to increase and the hydrolytic acidity to decrease. Among the other substances, it was charcoal that had the greatest influence on the soil properties, but the way it influenced the total exchangeable bases, the cation exchange capacity of soil and the degree of base saturation were opposite to the way calcium oxide influenced these properties.