Research of metallurgical slags chemical composition, originating both from current production as well as gathered in dumping grounds formany years, show that they are very diversified. Slags contain substantial amounts of metals, including heavy metals, apart from elements from groups of non-metals and lanthanoids. In the article occurrence forms and relations with phase components of selected metals (iron, manganese, zinc, lead and others) on the basis of mineralogical and chemical research on slags after steel and ore Zn-Pb production were characterized. It was stated that metals may occur in metallurgical slags as fine drops not separated from slag during a metallurgical process, may form polymetallic aggregates, their own phases (especially oxide ones) and hide in structures of silicate phases. A considerable amount of metals is dissipated in glaze and amorphous substance. The conducted research delivers information on the occurrence of metals in metallurgical slags, which is extremely important during work connected with economic exploitation of slags. It especially refers to increasing attempts of acquiring elements from metallurgical slags. These activities determine the necessity of analyzing chemical and phase composition of slags because they may be an important indication, for instance while working on a proper technology of elements recovery.