Hypervalent Sb...N bonding observed in triarylstibanes was investigated by single-crystal X-ray diffraction study, comparison of the 1 5 N chemical shifts, and HMBC NMR spectroscopic detection of the 1 H- 1 3 C long-range coupling. This bonding is strongly dependent on the Lewis acidity of the central antimony atom. A good correlation was observed between 1 5 N chemical shift and the charge distribution obtained from semi-empirical molecular orbital calculations.