In this work, the study of the6-chloro-4-hydroxy-3-phenyl pyridazine compound, (C-10 H-7 N-2 O Cl with synonym 4-pyridazinol, 6-chloro-3-phenyl-), was verified experimentally by using the Fourier Transformed Infrared (FT-IR), micro-Raman and UV/vis (in N,N-dimethylformamide solvent) spectroscopies. Furthermore, the optimized molecular geometry, conformatinal analysis, vibrational frequencies, the simulated UV/vis spectra (in gas and in N,N-dimethylformamide solvent), H-1 and C-13 NMR chemical shift (in gas, in chloroform and N,N-dimethylformamide in solvents) values, HOMO-LUMO analysis, the molecular electrostatic potehtial (MEP) surface and thermodynamic parameters ofthe6-chloro-4-hydroxy3-phenyl pyridazine compound were calculated by using DFT/B3LYP method with 6-311++G(d,p) basis set in ground state. The comparison of the calculated and vibrational frequencies with the experimental values provides important information about the title compound. (C) 2017 Elsevier B.V. All rights reserved.