A functionalized hexatungstate cluster bearing an organoimido ligand [W6O18(NAr)](2-), 1 (Ar=2,6-(i-Pr)(2)C6H3), is produced in the reaction of ArNCO with [Bu(4)N](2)[WO4]. 1 is a hydrolytically stable yellow material (lambda(max)=292 nm) that can be reduced to the corresponding trianion. Comparisons are drawn between 1, its Mo analogue, and its [W6O19](2-) relative.