Proton transfer processes in the ground and excited state of 4-methyl-2,6-dicarbomethoxyphenol (CMOH) have been investigated by means of steady-state and nanosecond transient spectroscopy in some nonpolar and weakly polar solvents at room temperature and 77 K. The results obtained for CMOH were compared with that of 4-methyl-2,6-diformylphenol (MFOH) reported previously. Unlike MFOH the fluorescence spectra of CMOH show dual emission. This was explained as due to the presence of both the enol tautomer and intramolecularly hydrogen-bonded closed conformer as the fluorescing species. At 77 K the emission spectra show phosphorescence only in the presence of a base like triethylamine. The fluorescence decay rates of CMOH are relatively slower than that of MFOH and the nonradiative rates are always found higher than the radiative rates. A theoretical calculation at the Austin model 1 level of approximation revealed that the excited-state intramolecular proton transfer barrier in the ground singlet and excited triplet states is rather large compared to the excited singlet state in the respective potential energy surfaces.