Vibrational contributions to the ? couplings of six mono- and five 1,1-di-substituted ethanes, three mono-substituted cyclohexanes, three norbornane-type molecules, and 11 three-membered rings have been calculated at the DFT/B3LYP level for the Fermi contact term using a moderate sized basis set. When, for a data set of 70 couplings, the sums of the values for the equilibrium configurations J e and the respective vibrational contributions ? at 300 K are multiplied by a factor of 0.8485, the corresponding predicted couplings ? are in good agreement with the experimental couplings ? with a standard deviation σ of 0.18 Hz. The same σ results when ? values are obtained by multiplying the J e values by 0.9016. However, the vibrational contributions must be taken into account, together with the J e values, in order to achieve a procedure for a reliable and accurate prediction of ? couplings since, globally, ? contributions amount to about 7% of the J e values and the correlation coefficient between ? and J e is only 0.68 with a σ deviation of 0.20. The first and diagonal second derivatives of J with respect to each normal coordinate Qk , required to estimate the vibrational contributions, have been obtained from six Jk values computed for molecular geometries positively ? and negatively ? displaced from the equilibrium geometry along the normal coordinate Qk and using for δ the values 0.01, 0.05 and 0.10. The computational precision of the results obtained when using one, two and three δ values is analysed.