Reaction of the gold(III) dihalide complexes [{C 6 H 3 (CH 2 NMe 2 )-2-R-5}AuX 2 ] (R=OMe, H; X=Cl, Br) with N,N -dimethylthiourea and silver(I) oxide in refluxing dichloromethane gave the novel gold(III) aggregate cations [{[{C 6 H 3 (CH 2 NMe 2 )-2-R-5}Au(μ-S)] 2 } 3 Ag 3 X 2 ] + , formed from the desulfurisation of the thiourea. The cations consist of three gold sulfide dimers doubly-bridged by three silver(I) cations, which in turn are triply-bridged by two halides. The aggregates have been fully characterised by 1 H- and 1 3 C-NMR spectroscopy and electrospray mass spectrometry (ESMS), which showed very strong parent ions that proved remarkably resilient to cone voltage induced fragmentation. Single crystal X-ray structures have been determined for two examples, although the nature of the counter-anion could not be unambiguously determined. The two X-ray studies show that both cis and trans isomers (with respect to the orientation of the N,N-dimethylbenzylamine ligands on either side of the Au 2 S 2 group) form, although only one isomer was isolated in each case. To compare this chemistry with that of platinum(II), cis-[PtCl 2 (PPh 3 ) 2 ] and N,N -dimethylthiourea were reacted in the presence of silver(I) oxide. Only the expected thiourea dianion complex [Pt{SC( NMe)NMe}(PPh 3 ) 2 ] formed, as observed in previously reported studies. The formation of the gold(III)-sulfido aggregates clearly demonstrates that gold(III) can have remarkably different chemistry to that of platinum(II). Reaction of [{C 6 H 3 (CH 2 NMe 2 )-2-OMe-5}AuCl 2 ] with N,N -diphenylselenourea in the presence of silver(I) oxide failed to give analogous selenium aggregates.