Tetracyanamidoaluminates of the type LiM₂[Al(CN₂)₄] with M = Eu and Sr were prepared by solid-state metathesis reactions departing from EuF₂ (or SrF₂), AlF₃, and Li₂(CN₂) in a 2 : 1 : 4 molar ratio. The ignition temperature of the exothermic formation of LiSr₂[Al(CN₂)₄] was obtained near 420 °C. An X-ray single-crystal structure refinement performed for LiEu₂[Al(CN₂)₄] revealed the presence of the novel homoleptic [Al(CN₂)₄]⁵⁻ ion in the structure. The X-ray powder diffraction pattern of LiSr₂[Al(CN₂)₄] was indexed isotypically.