The conductivities of blends of low-density polyethylene and poly(4-vinyl pyridine) (P4VP) were studied. The blends were synthesized by in situ sorption and thermal polymerization of 4-vinylpyridine in low-density polyethylene. They showed, after iodine doping, conductivities of 1.7 to 5.0 x 10(-7) S cm(-1) at 298 K, depending on the P4VP mass increment into the matrix. Their conductivities were one order of magnitude higher for measurements at 338 K. The optimum ratio of iodine to pyridine (n) which gave the highest conductivity was 0.21. The thermal stability of doped blends was acceptable for their uses as electrochemical devices.