AbstractSynthesis, crystal structure as well as IR‐ and Raman‐spectroscopic properties of the new ternary azidoaurates(III) A[Au(N3)4] (A = K, Rb, Cs) are reported. The translucent orange‐red compounds were prepared by reaction of the respective binary azides with HAuCl4 in aqueous solutions at room temperature. The crystal structures determined by single crystal X‐ray diffraction methods are monoclinic (C2/c (No. 15), K/Rb/Cs[Au(N3)4]: a = 1049.30(9) pm / 1033.93(10) pm / 1011.9(8) pm, b = 1047.52(8) pm / 1064.20(11) pm / 1093.8(8) pm, c = 776.97(7) pm / 809.79(8) pm / 858.4(6) pm, β = 91.220(5)° / 90.322(5)° / 92.72(5)°) and provide the first examples for azidoaurates with mono‐atomic cations. The unusual reduction of the lattice parameter a with increasing cation size in the isotypic series is discussed in detail. IR‐ and Raman‐spectroscopic measurements show strongly covalent gold‐nitrogen contacts, a bonding situation which is further supported by quantum chemical calculations and ELF‐analyses.