Problem of sewage sludge that is hazardous for natural environment is well known. Utilization of wastes is difficult due to often elevated heavy metals contents. Wastes are usually taken away to dumping ground. New methods for sewage sludge utilization taking into account their influence on the environment are still searched for. Therefore, it is useful to undertake studies leading to reduction of metal ions migration from wastes, to transfer them into hardly soluble compounds through dolomite application. Sewage sludge was treated with variable doses of dolomite (10, 20, 30%) for 6, 12 and 18 months. After that, sludge samples were treated with distilled water for 1 day and contents of metals were determined in filtrate using AAS technique. Distilled water mobilized the highest amounts of Pb, Mn and Zn from sewage sludge and that after dolomite treatment. Levels of mobilized ions: Mn, Cu, Cd, Fe and Cr decreased along with the increase of dolomite content Zn, Pb and Ni ions were mobilized in increasing amounts from sewage sludge containing increasing dolomite doses. Study results point out that application of 10% dolomite for sewage sludge treatment transferred heavy metals in hardly soluble compounds reducing their migration in an environment. Treated sewage sludge can be safely stored in the environment just after 6 months of seasoning.