A procedure for evaluating Raman optical activity (ROA) intensities using molecular orbital (MO) schemes is presented. In this procedure, molecular electric dipole polarizability is considered to be the sum of electric dipole polarizabilities of localized MOs. Then these orbital polarizabilities are treated in a manner similar to bond or atomic polarizabilities to formulate the molecular magnetic dipole and electric quadrupole polarizability tensors. In this model, termed as an orbital polarizability model, calculation of ROA intensities involves the evaluation of orbital polarizabilites, orbital centroids, and their normal coordinate gradients. These quantities, along with molecular structural parameters and atomic displacement vectors during normal modes of vibration, are noted to be sufficient to evaluate Raman scattering, vibrational infrared circular dichroism (VCD), and IR absorption intensities, also. Then an orbital polarizability model calculation of ROA intensities also provides, simultaneously, Raman, VCD, and IR intensities. Based on the finite electric field perturbative approach, which was originally utilized by Komornicki and McIver for evaluating Raman and IR intensities [J. Chem. Phys. 70, 2014 (1979)], ROA intensities have been evaluated for the first time using MO schemes. In this procedure, the gradients of orbital centroids and polarizabilities, with respect to nuclear coordinates, are expressed in terms of the gradients of orbital contributions to forces with respect to an applied electric field. It is pointed out that in this approach, one normal MO and force calculation, and 18 electric field perturbative calculations all at equilibrium molecular geometry, are sufficient to obtain all aforementioned vibrational intensities for all (3N-6) normal modes. We have also tested the validity and soundness of this efficient procedure by performing calculations on a simple optically active molecule NHDT and comparing the results with those obtained in an alternate procedure. In the alternate scheme, the normal coordinate gradients of orbital centroids and polarizabilities are evaluated from the MO calculations repeated at displaced nuclear geometries. In the comparison we noted that the former scheme provides better and sufficient numerical accuracy for ROA and Raman intensities, while the latter does not. We have also noted that while the IR intensities predicited by both procedures are identical, the VCD intensities match within a factor of 2. An explanation for this difference is provided.