Abstract: The present invention relates to a PTC composition comprising, by weight, the total being 100%: A) 40 to 80% of PVDF; B) 0 to 40% (advantageously 10 to 40%) of an acrylic or styrene polymer; C) 0 to 40% of an epoxy resin; D) 0 to 60% of at least one metal oxide; E) 0 to 25% of a carbonaceous conductive filler D+E being equal to at least 10%. To prepare the composition of the invention, the various constituents are blended in such a way that (A) is in the melt state, then the product obtained is extruded, moulded or injection-moulded or else deposited on a substrate. Once the composition has been converted into an article, for example into a sheet or bar, it is provided with at least two electrodes that serve as the power lead-in and return, respectively. The composition may also be placed between two conducting plates that serve as the power lead-in and return, respectively.