An iodine-filled iridium skutterudite compound was obtained by high-pressure and high-temperature reactions at 13 GPa and 850 degrees C from iodine excess starting mixtures. The structure and iodine content were refined by Rietveld analysis. The compound has a lattice constant of 9.3153(6) angstrom and the composition of I0.9Ir4Sb12. This compound contains anionic species in the skutterudite cages, although they are usually occupied by cations. This is, therefore, a rare member in the skutterudite family. Band structure calculations indicate that the compound is a metal with a conduction band highly contributed by iodine 5p orbitals.