In order to study the effect of mechanical activation on the sulphuric acid leaching of CuFeS2, four samples were milled using an Atritor mill during 1, 5, 8, and 15 h The powders were microstructural and morphologically characterized by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively The samples were leached using a solution of H2SO4 (0 54 M) at 298 K The Cu+2 concentration was determined by means of atomic absorption spectrophotometry The results obtained indicated that the increase in milling time results m increased recovery of Cu The maximum recovery of Cu was 38 2 % for a milling time of 15 h