The phosphorescenceo of [Rh(bhq)(2)Cl](2) was examined by a zero-field optical detection of magnetic resonance (zf-ODMR) method at 1.3 K, and the results were compared with those of the C-protonated ligand bhqH. The zero-field splittings of the complex are nearly identical to those of bhqH. For the complex, both the x- and z-sublevels emit equally strongly, whereas for the C-protonated ligand only the z-sublevel is effectively emissive. The spectral location, lifetime, and zero-field splittings indicate that the phosphorescence is from the ligand localized (3) pi pi* state somewhat perturbed by metal-to-ligand charge-transfer states. Due to the stronger ligand field provided by bhq and the negative charge of the ligand, two types of (3)d pi* states can configurationally mix with the bhq-localized (3) pi pi* state. The sublevel properties are satisfactorily interpreted in the framework of this configurational mixing.