IR spectra of salicylaldehyde (OH and OD) have been studied over a wide temperature range in the vapor phase, liquid Xe solution and Ar matrices. Far IR and Raman spectra have been obtained. Ab initio calculations at the 3-21G** level have been performed in order to establish the geometry of the molecule, normal coordinates and frequencies of vibrations. It has been found that profiles of both ν(OH) and ν(OD) bands are formed by the fundamental transition ν(s), by the weak sum transition ν(s) + ν₃, where ν₃ = 264 cm^-1 is an in-plane vibration involving deformation of the chelate ring with significant stretching of the intramolecular H- bond, and by a series of hot transitions from levels of ν₃ and other low frequency modes (ν(i)) of the chelate ring. The ν(OH) profile is perturbed additionally by several Fermi resonances with overtones and combinations of bending vibrations δ(OH). Anharmonicity constants, which characterize coupling of ν(s) with ν(i) and δ(OH), have been derived from the temperature dependence of the first spectral moments of the bands, using the results of the 3-21G** treatment. Model calculations of ν(OH) and ν(OD) band shapes have been performed.