The neutral excitations in poly(p-phenylenevinylene) are studied in conjunction with the vibronic structure of the lowest optical transitions. Combining the configuration interaction of Wannier-localized electron-hole pairs with an empirical description of electron-phonon coupling, we obtain the potential energy surfaces of monoexcited states and the Condon electron-vibrational spectra in absorption and emission. The S-1-->S-0 luminescence band shape is found compatible with self-localization of S-1 within about 10 monomers, driven exclusively by electron-phonon coupling. The singlet and triplet polaron-excitons are exchange-split by about 1 eV and differ substantially in terms of average electron-hole separation. (C) 2003 American Institute of Physics.