The electronic structure of IF is investigated using ab initio pseudopotentials and a variational/perturbative MRCI scheme (CIPSI/CIPSO). All the valence states dissociating into neutral asymptotes I(P-2(1/2), P-2(3/2))+F(P-2(1/2), P-2(3/2)) and ionic asymptotes I+(P-3(2), P-3(1), P-3(0), D-1(2), S-1(0))+F-(S-1(0)) are determined up to the region where they undergo avoided crossing with the neutral excited states dissociating into I*+F. The spectroscopic properties are derived and discussed in comparison with the available experimental results, with emphasis on the X, B, E, A, beta, A’, and D’ states.