In the new tin(IV) and copper(II) complexes, cis-dichlorido-trans-dimethyl-cis-bis(N,N′,N′′-tricyclohexylphosphoric triamide-κO)tin(IV), [Sn(CH3)2Cl2(C18H36N3OP)2], (I), and trans-diaquabis(N,N′,N′′-tricyclohexylphosphoric triamide-κO)copper(II) dinitrate–N,N′,N′′-tricyclohexylphosphoric triamide (1/2), [Cu(C18H36N3OP)2(H2O)2](NO3)2·2C18H36N3OP, (II), the N,N′,N′′-tricyclohexylphosphoric triamide (PTA) ligands exist as hydrogen-bonded dimers via P=O...H—N interactions around the metal center. The asymmetric unit in (I) consists of one complete complex molecule located on a general position. The SnIV coordination geometry is octahedral with two cis hydrogen-bonded PTA ligands, two cis chloride ligands and two trans methyl groups. The asymmetric unit in (II) contains one half of a [Cu(PTA)2(H2O)2]2+ dication on a special position (site symmetry inline image for the Cu atom), one nitrate anion and one free PTA molecule, both on general positions. The complex adopts a square-planar trans-[CuO2O2] coordination geometry, with the CuII ion coordinated by two PTA ligands and two water molecules. Each of the noncoordinated PTA molecules is hydrogen bonded to a neighboring coordinated PTA molecule and an adjacent water molecule; the phosphoryl O atom acts as a double-H-atom acceptor. The P atoms in the PTA ligands of both complexes and in the noncoordinated hydrogen-bonded molecules in (II) adopt a slightly distorted tetrahedral environment.