Mu-(Pyrazolyl-N:N')-bis[(2,2',2"-terpyridine)platinum(II)] perchlorate acetonitrile solvate, [Pt2(C15H11N3)2(C3H3N2)](ClO4)3.CH3CN, M(r) = 1263.18, orthorhombic, Pnma, a = 18.172 (2), b = 17.950 (3), c = 12.086 (4) angstrom, V = 3942.3 (15)angstrom3, Z = 4, D(x) = 2.128 g cm-3, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 74.41 cm-1, F(000) = 2416, room temperature (297 K), R = 0.0337 for 25 1 0. reflections with F(o)2 > 3-sigma(F(o)2). A single pyrazolyl unit bridges two Pt centres. The square-planar coordination around each Pt atom is completed by a tridentate terpyridine ligand. The Pt ... Pt separation is 3.432 (1) angstrom with an inclination of 47.7 (12)-degrees between the two Pt square planes.