In the present work, (Ba 0 . 8 5 Pb 0 . 1 5 )TiO 3 -based positive temperature coefficient resistors (PTCRs) with low room-temperature resistivities were produced, and the effects of composition and processing conditions on materials electrical properties were investigated. For (Ba,Pb)TiO 3 -based ceramics, it was noted that an addition of double donors Sb 2 O 3 +Nb 2 O 5 led to a lower room-temperature resistivity than that of single donor Nb 2 O 5 . The resistivity followed to reduce when properly increasing the donor concentration and decreasing the acceptor (MnO 2 ) concentration. The correlation of sintering temperature with ceramic parameters, namely, density, grain size, room-temperature resistivity, resistivity jump, and room-temperature breakdown strength, was discussed. Metal Cr was added to ceramic matrix to further reduce the resistivity. A reducing sintering and a subsequent oxidation treatment processes were employed, and the influences of metallic content and processing conditions on composite density, room-temperature resistivity, and room-temperature breakdown strength were analyzed. Low room-temperature resistivity PTCRs were produced by controlling both Cr content and the processes.