Fluorine-19 NMR analyses allowed to obtain kinetic data about bicyclo[2.2.2]oct-7-ene dianhydrides thermal imidization. It was evidenced that the high reactivity of such a substrate is owing to the combined effects of bifunctionality and ethenylene bridge. This latter effect is inhibited by the presence of an electron-withdrawing group on the double bond. A basic solvent (NMP) does favor the amic acid intermediate formation; an acidic solvent (m-cresol) does accelerate the amic acid cyclization to imide,