A novel octanuclear vanadium(V) oxide cluster complex, [V8O20(4,4'-(t)Bubpy)(4)] (1), was synthesized and characterized by single-crystal X-ray structure analysis to reveal that 1 has an unprecedented neutral V8O20 core. An unexpected interconversion between 1 and the methoxo(oxo)vanadium(V) cluster complex, [V4O8(OMe)(4)(4,4'-(t)Bubpy)(2)] (2), was observed upon changes in the solvent systems.