In this paper, vibrational spectra of tolazamide have been investigated by ab initio techniques in combination with experimental studies. Data on the FT-IR spectra (400-4000 cm(-1)) and Laser-Raman spectra (100-4000 cm(-1)) of tolazamide have been obtained in the solid phase. Assignments corresponding to the vibrational frequencies have been found and interpreted by the contribution of the potential energy distributions. The theoretical results are compared X-ray experimental data for this. Structural parameters such as bond lengths and angles, frequencies and intensities regarding Raman and IR spectra of the compound have been computed by density functional theory and Hartree-Fock methods with 6-311G++(d,p) and 6-31G(d) basis sets. They have been observed that the computed vibrational frequencies and optimized structural parameters are consistent with the corresponding experimental results. In addition, the images of frontier molecular orbitals (highest occupied and lowest unoccupied) have been presented and interpreted. (C) 2015 Elsevier B.V. All rights reserved.