The o-hydroxy Schiff bases consisting of N'-[(Z)-(2-hydroxy-4-methoxyphenyl)methylidene]pyridine-4-carbohydrazide and N'-[(Z)( 2-hydroxy-4-methoxyphenyl) methylidene]pyridine-3-carbohydrazide were prepared by reaction of isonicotinic acid hydrazide and nicotinic acid hydrazide by employing 2-hydroxy-4-methoxy benzaldehyde. The spectroscopic techniques, X-ray crystal structure determination as well as DFT calculations have been carried out to shed light on the nature of hydrogen bonding. The both experimental and theoretical investigations demonstrate the presence of intramolecular neutral hydrogen bonding (enol-imine type) in these molecules.