A bicyclo [3.3.0] octane-like core consisting of eight bismuth atoms is found in the novel octabismuthane Bi-8[Sn(SiMe3)(3)](6). It is prepared like Bi-4[Si(SiMe3)(3)](4) by reduction of BiBr3 with Li(thf)(3)E(SiMe3)(3) (E = Si, Sn) together with (Me3Si)(6)E-2. Both bismuth ring compounds have been characterized by single crystal X-ray crystallography.