Ga2Cl4 reacts with hexam ethylbenzene in benzene to give (hexam ethylbenzene)gallium(I)tetrachlorogallate(III), (CH3)6C6G a+GaCl4_ , in high yield. The com plex crystallizes in the rhombohedral space group R 3m with four formula units per cell. Cell constants are a = 12.449(3) Ä and a = 91.01(2)°. In the structure tetrameric clusters can be identified contain ing two crystallographically independent formula units, one having 3 m and the other three having m symmetry. In both types of (arene)Ga^ cations the Ga atoms are symmetrically positioned over the arene ring, 2.43(3) and 2.51(3) Ä , respectively, away from the ring plane. Four (arene)G a+ cations and four GaCl4 anions are aggregated in such a way that the G a1 atoms are surrounded by six or seven chlorine atoms, respectively, at distances in the range 3.16(1) to 3.67(1) A . The four hexamethylbenzene molecules form an efficient cover around the inorganic [Ga~GaCl4“]4 framework. Between the tetrameric clusters there are no contacts of the G a’ -Cl Tvpe.