Abstract We report the synthesis and crystal structure of the new compound Sr 4PbPt 4O 11, containing platinum in highly unusual square pyramidal coordination. The crystals were obtained in molten lead oxide. The structure was solved by X-ray single crystal diffraction techniques on a twinned sample, the final R factors are R = 0.0260 and w R = 0.0262 . The symmetry is triclinic, space group P1¯, with a = 5.6705 ( 6 ) Å , b = 9.9852 ( 5 ) Å , c = 10.0889 ( 5 ) Å , α = 90.421 ( 3 ) ° , β = 89.773 ( 8 ) ° , γ = 90.140 ( 9 ) ° and Z = 2 . The structure is built from dumbell-shaped Pt 2O 9 entities formed by a dinuclear metal–metal bonded Pt 2 6+ ion with asymmetric environments of the two Pt atoms, classical PtO 4 square plane and unusual PtO 5 square pyramid. Successive Pt 2O 9 entities deduced from 90° rotations are connected through the oxygens of the PtO 4 basal squares to form [Pt 4O 10 8−] ∞ columns further connected through Pb 2+ and Sr 2+ ions. Raman spectroscopy confirmed the peculiar platinum coordination environment.