The contribution of stereoelectronic interactions to NMR coupling constants (3)J(HH) and (4)J(HH) has been examined using ab initio calculations and natural bond orbital (NBO) analysis on four model compounds: ethane, propane, propene, and methylcyclopropane. The main stereoelectronic contributions to the couplings originate in three-bond (vicinal) interactions and in through-space interactions. In ethane, besides the main contribution of the sigma(C-H) --> sigma*(C-H) interaction, other interactions present in the molecule make a decisive contribution to the angular dependence of (3)J. In the H-1-C-C-C-H-anti moiety of propane, (4)J(HH) has important contributions from vicinal interactions that include the anti proton while in the H-1-C-C-C-H-gauche moiety the main contributions are vicinal interactions that include H-1. In alkene fragments, vicinal interactions that involve the a orbitals are the most important contributions to the couplings. Sigma vicinal interactions, which include orbitals corresponding to C-H bonds that involve either of the coupled protons, are crucial to elucidate differences between cisoid and transoid coupling constants. In the case of methylcyclopropane, the most important contributions to the coupling of the syn cyclopropyl H come from the sigma(C-H) --> sigma*(C-cyclopropane-C-cyclopropane) and sigma(C-cyclopropane-C-cycloprapane) --> sigma*(C-H) vicinal interactions (where the H corresponds to the non-cyclopropyl hydrogen). The concerted effect of several interactions that contribute toward a trend similar to that shown by allyl-vinyl proton couplings is in accordance with a significant T contribution of the C-cyclopropane-C-cyclopropane bond. For the anti cyclopropyl proton, vicinal interactions of the form sigma(C-H-anti) --> sigma*(C-cyclopropane-C) and sigma(C-cyclopropane-C) --> sigma*(C-H-anti) are the main contributors to the angular variation of the couplings, similar to what happens to the anti proton in propane. As a whole, the overall behavior of these couplings resembles that of the equivalent proton in propane. In addition, in this case there is not a unique set of interactions which accounts for the overall angular variation of (4)J.