Pyrometallurgical treatment of sulphide concentrates generates SO 2 and, hence, atmospheric pollution. An attractive alternative for metal recovery could be the use of microorganisms due to its low cost and relatively fewer pollution problems compared with conventional hydrometallurgical and pyrometallurgical processes. Bacterial leaching is being commercially well exploited for the copper recovery from low-grade ores. In the present investigation the possibility of copper recovery from a copper sulphide flotation concentrate containing: 29.1% Cu. 21.9% Fe, 1.54% Zn and 23.2% S has been evaluated using both mesophilic and thermophilic microorganisms. Bacterial leaching of copper sulphide flotation concentrates is a complex process, which occurs at a sequential way: chalcocite and digenite are the first minerals to be dissolved, followed by chalcopyfite. Optimal copper recovery was achieved using a moderate thermophilic culture at 45°C. Copper dissolution reached 85% with a copper concentration of 13.8 g/L in solution.