Tetrahedral AuI complexes [L3Au(SnCl3)] (L=PMe3 (1), PMe2Ph (2), PMePh2 (3), and PPh3 (4)) were prepared by treatment of the [(tht)Au(SnCl3)] (tht=tetrahydrothiophene) complex with three equivalents of the corresponding tertiary phosphine. The crystal structures of complexes 1–4 have been determined through X-ray diffraction studies showing, in all cases, [SnCl3]− fragments covalently bonded to the corresponding [Au(PR3)3]+ units, which leads to a tetrahedral coordination environment for gold. Complexes 3 and 4 show phosphorescence in the solid state at room temperature and 77 K that is largely redshifted relative to the free [Au(PR3)3]+ and [SnCl3]− counterparts. Correlated MP2, SCS-MP2, and ONIOM MP2/UFF calculations suggest a largely distorted lower triplet excited state (T1) for each model system. The AuP3+ moiety is distorted leading to a T-shape, whereas the SnCl3− unit is left almost unaltered. Molecular orbital and population analysis suggest that the emission of these tetrahedral AuI complexes arises from a 3MC transition slightly perturbed by the SnCl3− fragment.