The extraction behaviour of Cu(II) from hydrochloric acid and lithium chloride solutions with di-n-pentyl sulphoxide (DPSO) and di-n-octyl sulphoxide (DOSO) has been investigated over a wide range of conditions. At a given strength of the extradant, the extraction increases with increase in HCl and LiCl concentrations. The extraction of the metal also increases with increase in extractant concentration at constant [HCl] or [LiCl]. The species extracted would appear to be CuCl2·2DPSO/2DOSO and CuCl42−·2DPSO. The extraction of the metal decreases with increase in initial aqueous metal concentration and also with increase in temperature. The extraction also depends on the nature of the diluent employed.