The platinum(IV) complex [PtH 3 (triphos)] + (1) is formed upon treatment of [PtCl 2 (triphos-P,P )] with NaBH 4 . The complex 1 reacts with 3 equiv. of [AuCl(PPh 3 )] to give the tetrahedral PtAu 3 cluster [Pt(triphos)(AuPPh 3 ) 3 ] + (2). The complexes 1 and 2 are characterised by one- and two-dimensional multinuclear NMR spectroscopy. The platinum atom of 2 is bonded to the three phosphorus atoms of the triphos ligand and to three gold atoms giving a six-coordinate Pt atom. The cation has a crystallographically imposed threefold axis defined by the Pt atom and the centre of the Au 3 triangle. Some distances and angles: Au-Au 285.80(8), Pt-Au 262.99(8)pm, Au-P 226.9(3) pm, Pt-P 231.2(3), Au-Au-Pt 57.088(13)°, Au-Pt-Au 65.82(2)°.