AbstractThe new tungsten bromide cluster compound Bi2W6Br18 was synthesized by reacting tungsten hexabromide with bismuth metal in a silica tube at 350 °C. The structure of Bi2W6Br18 was refined by single‐crystal X‐ray diffraction in the space group P21/c with unit cell dimensions of a = 981.8(2) pm, b = 1305.9(2) pm, c = 1256.8(2) pm and β = 101.81(2)°. The crystal structure is constructed from [(W6Br8i)Br6a]2–anions being interconnected by outer bromine ligands with (BiBr2) units that behave as cations in (BiBr2)2[(W6Br8)Br6]. Short Bi–Br bonding distances at 261.3(1) pm and 265.9(2) pm in (BiBr2) units suggest the presence of covalent interactions. Thermal decomposition of the compound leads to W6Br12.