Hexathia-18-crown-6 (HT18C6) was used as a specific ion carrier for the transport of silver ion through a chloroform bulk liquid membrane. In the presence of thiosulfate ion as a suitable stripping agent in the receiving phase, the amount of silver transported across the liquid membrane after 60 min is 99.5+/-1.0%. The selectivity of Ag + transport from the aqueous solutions containing other M n + cations such as Tl + , Mg 2 + , Ca 2 + , Mn 2 + , Co 2 + , Ni 2 + , Cu 2 + , Zn 2 + , Cd 2 + , Pb 2 + , Hg 2 + , and Cr 3 + ions was investigated. Except with Hg 2 + ion, non of the cations used interfere the silver transport, even at a M n + /Ag + molar ratio of 500. The interfering effect of Hg 2 + ion was successfully eliminated in the presence of EDTA at pH 5.