Thermal treatment of metal finishing waste with locally available clay, in their varying ratios, was carried out at 850°C and above temperatures. In the presence of 1:1 ratio of waste and clay a solidified product was obtained at 950°C. Measurement of an appreciably high compressive strength, ∼ 500 kg cm-2 and a very small (0.4%) water absorption from the solidified product indicated its stable nature. Toxicity Characteristic Leaching Procedure (TCLP) test of the waste showed nearly 85 to 90% decrease of leaching of Fe, Cu, Ni, Zn, Mn and Cr after thermal treatment compared to their leaching without treatment. No hexavalent chromium{Cr(VI)} was observed from the leachate of the solidified product. This indicates the absence of re-oxidation phenomena of chromium during thermal treatment up to 950°C. X - ray diffraction (XRD) of solidified product indicated the presence of hematite, and aluminum silicate as main phases of the solidified product. Involvement of the above waste metals with these phases during thermal treatment could be the reason for their immobilization. [ABSTRACT FROM AUTHOR]