Vibrational optical activity associated with the peptide group vibrations has been examined with N-methylacetamide (NMA) as a model compound. In this process, the structures and vibrational infrared and Raman spectra of NMA are also examined. The ab initio Hartree-Fock investigations with the 6-31G* basis set and higher level calculations using electron correlation (MP2/6-31G*) and a larger TZP basis set indicate that the chiral structures have energies comparable to, and some times slightly lower than, the energies of the achiral structures. The predicted absorption spectra for chiral and achiral NMA conformers are similar and consistent with the corresponding experimental spectra of NMA. However, the predicted Raman spectra of the chiral. and achiral conformers show significant differences. The predictions for vibrational optical activity of the chiral conformers suggest that the vibrations of carbonyl and of methyl groups are especially sensitive to the conformation of peptide groups. These investigations are expected to serve as reference points for the interpretation of the experimental vibrational optical activity spectra of peptides.