The polarized optical absorption and emission of single crystals of [(C2H5)4N]2[Pd(mnt)2] (mnt = [S2C2(CN)2]2-) at temperatures 3 K less-than-or-equal-to T less-than-or-equal-to 295 K are reported. The lowest excited states are due to 1,3B3g and 1,3B2u terms with metal-to-ligand charge-transfer and ligand-centered character, respectively. Vibronic structure is observed on the lowest energy absorption band and on the emission band. The energy spacings and the intensities of the vibronic bands are analyzed.