Penicillin G was extracted using a secondary amine, Amberlite LA-2, as a carrier by emulsion liquid membranes (ELMs) in a batch system, where a dilute polymer solution was used as the organic membrane phase, which followed non-Newtonian behavior. The effect of the concentrations of the polymer and surfactant in the membrane phase on the extraction of penicillin G was investigated. To analyze the ELM system, the emulsion swelling and viscosities of the membrane and emulsion phases were also measured before or after the extraction. With the addition of a small quantity of polymer to the membrane phase, the emulsion swelling was reduced without any decrease in the final degree of extraction. Accordingly, the applicability of ELM processes with use of a dilute polymer solution to penicillin G extraction would appear to be promising.