The paper describes synthesis of (n‐Bu4N)2[RuNOCl5](I), (n‐Bu4N)2[RuNOCl4OH](II), (n‐Bu4N)2×[RuNOCl4OH]·6H2O (III), and (n‐Bu4N)2[RuNOCl5]· 2(n‐Bu4N)2[RuNOCl4(H2O)]·2H2O (IV). The complexes were studied by IR spectroscopy and powder X‐ray and crystal X‐ray analyses. The structures are built up of [RuNOCl5]2- (I, IV), [RuNOCl4OH]2- (II, III), and [RuNOCl4(H2O)]- (IV) complex anions, (n‐Bu4N)+ cations, and crystal water molecules (III, IV). The substances are moderately soluble in water; highly soluble in polar organic solvents, such as acetone, ethanol, chloroform, methylene chloride; and almost insoluble in carbon tetrachloride and toluene. Under storage in light, the compounds decompose from the surface; in darkness I and II are stable, whereas III and IV can lose part of the crystal water.