The crystal and molecular structures of two new phosphorochromones determined by single-crystal X-ray diffraction are presented. The existence of two tautomers stabilized by intramolecular N-H...O and O-H...N hydrogen bonds and environmental effects in crystals is observed as evidence of the proton transfer reaction. The proton transfer process within simple enaminones being Analogues of the compounds studied by X-ray diffraction methods is investigated usingMP2/6-311++G** and MP4/6-311++G** levels of theory. The Bader theory is also applied in the analysis of the hydrogen bonding within investigated systems. The results indicate that the systems with N-H...O intramolecular hydrogen bonds are more stable than those containing O-H...N bonds.