The title compound, (C9H14N4)[CoCl4], a methylene-bridged bis-imidazolium salt containing a tetrachlorocobaltate anion, is one of the first examples where an alkyl-bridged bisimidazolium compound could be structurally characterized. Short C - H ... Cl contacts between the imidazolium C - H bonds and the Cl atoms of the counter-anion build up a three-dimensional network and indicate that the C - H bonds are strongly polarized.