The reactions of PbPh 2 (OAc) 2 with alkylglyoxylate thiosemicarbazones (HRGTSC, R=Et, Bu) afforded complexes of the type [PbPh 2 (GTSC)]·H 2 O, [PbPh 2 (RGTSC) 2 ] and [PbPh 2 Cl(BuGTSC)]. The structures of HRGTSC (R=Me, Et, Bu), [PbPh 2 (OAc)(RGTSC)](R=Me, Et, Bu), [PbPh 2 Cl(BuGTSC)] and [PbPh 2 (GTSC)]·H 2 O have been studied by X-ray diffraction. [PbPh 2 (OAc)(RGTSC)] and [PbPh 2 (GTSC)]·H 2 O have [PbC 2 NO 3 S] kernels and the coordination sphere of the metal is pentagonal bipyramidal. [PbPh 2 Cl(BuGTSC)] has a [PbC 2 NOSCl] kernel and the coordination geometry around lead is pentagonal bipyramidal with one vacant site. Analysis of the bond distances in [PbPh 2 (GTSC)]·H 2 O suggests a significant affinity between diphenyllead(IV) and carboxylate donor groups, supporting a borderline acidic character for this organometallic cation. 1 H and 13 C NMR spectra in DMSO-d 6 suggest the partial dissociation of the acetate in [PbPh 2 (OAc)(RGTSC)] solutions and indicate some differences in the coordination mode of the two RGTSC − ligands in [PbPh 2 (RGTSC) 2 ] complexes.