Ten substituted benzoate complexes of Pr3+ of the type [Pr(XC6H4COO)(3)(H2O)(n)(DMF)(m)](p)center dot(DMF)(q) (X = OCH3, NO2, OH, F, Cl, NH2) have been synthesized, and for eight of these crystallographic data are available. The electronic absorption and emission spectra of the complexes have been recorded and interpreted at temperatures down to 10 K for transitions involving the P-3(0) and D-1(2) J-multiplet terms. Generally, the electron-withdrawing groups X in the benzoate moiety lead to higher P-3(0) energy than electron-donating groups. Empirical relations have been found between the energies of the P-3(0) and D-1(2)(1) levels and the Hammett sigma constants for substituents and the unit cell volume per Pr3+ ion. The latter relationship is indicative of a correlation between the electronic state energy and the ligand dipole polarizability. This has been confirmed by reference to literature data for the LaX3:Pr3+ systems, so that the ligand dipole polarizability is a key factor in determining the nephelauxetic shifts of 4f(N) ions in crystals.