Hexaamidostannates(IV) of the alkali metals potassium, rubidium and caesium were prepared by the reaction of tetraphenyl tin with alkali amides in an autoclave made of stainless steel at 385 K with ammonia as solvent. Single crystals were obtained in the form of colourless, transparent hexagonal plates.Their structures were solved by X-ray methods including all hydrogen positions for K 2 [Sn(NH 2 ) 6 ] in the space group R3 with Z = 3 (hexagonal setting), and for Rb 2 [Sn(NH 2 ) 6 ] and Cs 2 [Sn(NH 2 ) 6 ] in the space group P3 with Z = 1.Both structure types contain isolated octahedra units [Sn(NH 2 ) 6 ] 2 - . Potassium is coordinated trigonal anti-prismatically by 6 amide ions, rubidium and caesium anti-cuboctahedrally by 12 amide ions. The orientation of the hydrogen atoms is related to the size of the alkali metal ions.