Potassium-dicyclohexyl-18-ci-own-6 was used as a selective and efficient carrier for the uphill transport of thallium (111) ion as [TICl4] complex ion through a chloroform bulk liquid membrane. By using oxalate anion as a metal ion acceptor in the receiving phase, the amount of thallium (111) transported across the liquid membrane after 120 min was 96 +/- 2%. The selectivity and efficiencies of thallium transport from aqueous solutions containing Cu2+ Zn2+, Ni2+ Cd2+ Pb2+, Co3+, Mn2+ Cr3+ Mg2+, Ca2+, K+, Na+, and Fe3+ ions were investigated. In the presence of Na3PO4 (0.01 M) at pH = 3 as a suitable precipitation agent in the source phase, the interfering effect of Pb2+ ion were diminished drastically.