The contact contribution to13C-H,13C-13C and to geminal and vicinal coupling constants is calculated according to Pople and Santry's theory using molecular orbital wave functions developed by Newtonet al.(NEMO wave functions). The calculated13C-H and13C-13C coupling constants are in better agreement with experiment than those obtained by the EHT or CNDO method. This must be due to the inclusion of carbon 1sorbitals in the LCAO basis set of the NEMO wave function.