The aim of the experiments was to determine the effect of cadmium-contaminated soil (10, 20, 30 and 40 mg Cd · kg^-1 soil) on the magnesium content in oats, maize, yellow lupine and radish. Compost, brown coal, lime and bentonite were added to reduce the undesirable effect of cadmium contamination on the plants. As a result of soil contamination with cadmium, the amount of magnesium increased in all the examined parts of the oats, in the above-ground parts of yellow lupine and radish as well in the roots of maize.The application of compost, lime, bentonite and especially brown coal into the soil had an overall positive effect on the magnesium content in the vegetative parts of the crops. The magnesium content in the plants was generally correlated with the accumulation of other macro- and some microelements.