The aim of the study was estimation of the direct and consequential effect of fertilisation with compost from municipal wastes and compost from “green” wastes and other biodegradable wastes on the content of selected heavy metals (Cr, Pb, Cd, Ni) in maize biomass and on the content of available forms those elements in soil. The nitrogen dose applied per pot (8.60 kg of air-dry soil material) in the first year of the study in fertilised treatments was 1.00 g. In the case of treatments in which the organic materials were applied, the dose of nitrogen was introduced in whole with those materials, or as a divided dose (0.50 g N with the organic material + 0.50 g N in mineral form, NH₄NO₃). For comparison, fertilisation with chemically pure mineral salts and with swine manure was applied. The largest quantity of biomass, both aboveground parts and roots, was obtained in the first year of the study, in the treatment in which fertilisation with mineral salts was applied. In the second year, significantly the highest yields of maize biomass were obtained in treatments with composts or manure. The study showed also a positive response of maize to organic fertilisation applied in conjunction with mineral fertilisation. The introduction of considerable amounts of heavy metals into the soil with the compost from non-segregated municipal wastes did not cause their excessive accumulation in maize. Higher levels of available forms of the heavy metals under study were assayed in the soil immediately after the application of the composts than in the second year.