A trimetallic Hg(II)-Pt(II)-Hg(II) complex, [Hg2Pt(CH2P(S)Ph2)4]X2 (X = BPh4, PF6), was obtained from the reaction of Hg(MTP)2 (MTP = CH2P(S)Ph2) with 1 equiv of Pt[S(CH2CH3)2]2Cl2, in CH2Cl2, in the presence of either NaBPh4 or TlPF6. The X-ray crystal structures of these compounds show the ylide ligand bridging the three metals with Hg...Pt distances of 3.016(1) and 3.138(1) angstrom, respectively. In contrast to the isoelectronic and structurally similar Au2Pt(MTP)4 complex, the trimetallic cationic units are each nonlinear, with angles of 166.3(1) and 149.1(1)-degrees for the BPh4- and PF6- salts, respectively. Unlike Au2Pt(MTP)4, the mercury-platinum complex reacts with halogens to give Hg-C bond cleavage products. No materials are formed which contain Hg-Pt bonds. Crystallographic details for [Hg2Pt(CH2P(S)Ph2)4](PF6)2.1/2C2H4Cl2 are as follows : triclinic space group P1BAR, a = 11.264(9) angstrom, b = 13.666(3) angstrom, c = 20.930(5) angstrom, alpha = 107.965(1)-degrees, beta = 94.548(1)-degrees, gamma = 94.848(1)-degrees, Z = 2, and R = 0.0387 for 5032 reflections where F(o)2 > 3sigma(F(o)2).