Methyl red was used as an excellent carrier for the uphill transport of Hg(II) through bulb liquid membrane. By using iodide as a metal acceptor and in the presence of sulfuric acid in receiving phase the amount of mercury transport across the bulb liquid membrane was about 90% after 180 min. By replacement of the above receiving phase with 0.45 M HCl, a simpler and more reproducible system was obtained. Oleic acid was used to overcome a minor leaching of the carrier into the aqueous phase at high acid concentration. This system was optimized with a simplex optimization program. Under optimum conditions, the amount of Hg(ll) transport across the liquid membrane is about 80% after 150 min. The carrier can selectively and efficiently transport Hg2+ ion from aqueous solution containing other cations such as Cd2+, Zn2+, Cu2+, Mg2+, Ca2+ Ag+, Ni2+, Al3+, Na+, Pb2+, Fe3+ and Pd2+.