Conductivity enhancement was observed in the polymer gel [cross-linked poly(N-vinyl-2-pyrrolidinone), c-PVPD], swollen with N-methyl-2-pyrrolidinone, NMP containing the surfactant (sodium deoxycholate, NaDC) as an electrolyte salt. The enhancement was induced by the aggregate formation of the NaDC and the ensuing increase of the number of charge carriers in the gel. Such enhancement of conductivity was not observed in the NMP solution containing NaDC, or NaDC and linear poly(N-vinyl-2-pyrrolidinone, 1-PVPD. It is suggested that the polymer chains in the gel matrix participate in the enhancement of the conductivity.