Synthesis, crystallographic characterization, spectroscopic and density functional modelling studies of the 2-isopropylbenzimidazolium tetrachloroplatinate monohydrate (C10H13N2)(2).[PtCl4]. H2O have been reported. The molecular structure of the compound was determined by single-crystal X-ray diffraction analysis. In the compound, the Pt atoms reside at a center of inversion. The compound is comprised of 2-isopropylbenzimidazole (Hipb)(+): (C10H13N2)(+) and [PtCl4](2-) ions, respectively, linked by intermolecular hydrogen bonds N center dot center dot center dot Cl [3.249(4) from 3.660(7) angstrom], C center dot center dot center dot Cl [range from 3.553(7) to 3.895(7) angstrom] and O atom of a non-coordinating water molecule in the crystal structure N center dot center dot center dot O [2.728(8) angstrom], O center dot center dot center dot Cl [range from 3.234(6) to 3.451(7) angstrom], C center dot center dot center dot O [range from 3.350(7) to 3.545(1) angstrom] for the investigated compound. The molecular structure obtained from X-ray single-crystal analysis of the investigated compound in the ground state has been compared using Hartree-Fock (HF) and density functional theory (DFT) with the functionals B3LYP and PBE1PBE using the LANL2DZ basis set. The experimental and calculated vibrational frequencies of the title compound have been compared. There exists a good correlation between experimental and theoretical data for the complex.