Two-stage countercurrent oxygen pressure acid leaching process was developed to recover valuable metals from Gacun complex copper concentrate. It is unusual that tetrahedrite, whose treatment has been rarely studied, is the primary copper mineral of a concentrate. Most of silver also occurs in the mineral. The optimum operating parameters of the first stage and the second stage were established by conditional tests. Pilot scale tests ran smoothly, and the average overall leaching percentages of copper and zinc were as high as 96.2% and 97.5% respectively while the average overall leaching percentages of Fe, As and Sb as impurities were only 8.5%, 6.5% and 0.8%. Pb and Ag were not dissolved and stayed in the second stage leaching residue. (C) 2011 Elsevier Ltd. All rights reserved.