“Wartowice” tailings pond was closed in 1989, resulting in 232,4 ha tailings pile requiring reclamation. The major problem is heavy metals presence and poor nutrient conditions and physicochemical structure of soil which disturbs the plants development. In order to assess the real condition of studied area the complete biological characteristic has been done. The physicochemical conditions were assessed altogether with phytosociological, microbiological and toxicological studies of deposits. We recorded only 27 species of vascular plants belonging to 15 families on the tailings pond of which 5 belong to Rosaceae, 4 to Asteraceae and 3 to Poaceae and Saliceae. Species inhabiting the tailings depended on their dispersal capacity, metal tolerance and rhizome strategy. Microbiological analyses revealed the low number of bacteria and fungi on the tailings pond, apart from the small uplift area where the plants were indentified. Bacteria identified on the tailings pond were classified to 8 genera. The low number of bacteria suggests the lack of nutrients which affects the development of soil microflora. Toxicity tests showed that post-flotation sludge is not toxic to microorganisms because of its high pH. Some plants, such as lucerne could even influence positively the microorganisms development what has been proved in our studies. The tailings toxicity was higher towards producers, where Secale cereale appeared to be the most sensitive species. Amendment with topsoil from adjacent areas can influence positively the phytotoxic properties of tailings and enrich them into native seeds.