Two-color two-photon ionization experiments were performed in order to analyze the one-color resonance-enhanced two-photon ionization (R2PI) spectra of room-temperature naphthalene. The data provide Franck-Condon (FC) factors connecting the S/sub 1/ state to the ground-state cation, and vibrational frequencies for the cation. The geometry and frequencies of the cation are close to those in the S/sub 1/ state. The spectra suggest that intramolecular vibrational redistribution occurs on a time scale less than 5 ns for S/sub 1/ vibrational levels with 1800 cm/sup -1/ or more energy. The one-color R2PI spectra are consistent, within experimental error, with predictions based on an incoherent rate equation model.