The double photoionization of N2O molecules, in the 28-40 eV energy range, has been studied by synchrotron radiation. In the whole energy range, dissociative ionization producing N+ + NO+ or N-2(+) + O+ has been observed. Below similar to 35.5 eV, these two processes involve the formation of some antoionizing states. In the range between similar to 35.5 and similar to 38.5 eV the two processes occur instead by a direct coulomb explosion of the N2O2+ dication. Above similar to 38.5 eV the dissociation leading to NO+ + N+ is also promoted by the formation of a dication metastable state which decays by fluorescence to the ground state and then dissociates. (c) 2006 Elsevier B.V. All rights reserved.