Favorable positive temperature coefficient (PTC) properties of multiwall carbon nanotubes (MWCNT)/poly(vinylidene fluoride) (PVDF) nanocomposites were obtained. The results showed that such composites presented high PTC intensity, as well as eliminated negative temperature coefficient effect and high thermal stability, which indicated that the MWCNT/PVDF nanocomposites could overcome the main shortages of the current polymer-based PTC composites. By comparing with other contrastive nanocomposites through similar procedure, the mechanisms for the MWCNT/PVDF composite to overcome the shortages were studied and discussed. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 116: 838-842, 2010