The dinuclear osmium polyhydride [Os2H7((PPhPr2)-Pr-i)(4)][HC(SO2CF3)(2)] (1) was synthesized by the protonation of [OsH6((PPhPr2)-Pr-i)(2)] with bis(trifluoromethylsultonyl)methane. Treatment with amine bases was not able to deprotonate 1, but reaction with potassium hydride gave the corresponding neutral polyhydride [Os2H6((PPhPr2)-Pr-i)(4)] (2). Single crystal X-ray diffraction revealed that 1 and 2 both crystallize in the P2(1)/c space group and are classical polyhydrides containing similar Os(mu-H)(3)Os cores with Os-Os distances of 2.5431(1) angstrom and 2.5448(2) angstrom, respectively. These structures represent rare examples of dinuclear osmium polyhydrides with six or more hydride ligands.