1-(2-Chlorophenyl)-3-(thiophen-2-yl)-1H-pyrazole-4-carboxaldehyde (3) was synthesized by the reaction of (Z)-1- (2-chlorophenyl)-2-(1-(thiophen-2-yl)ethylidene)hydrazine (2) and Vilsmeier-Haack (DMF, POCl3) reaction. The synthesised compound was characterized by spectroscopy and elemental analysis. The crystal structure was determined from single crystal X-ray diffraction data. It crystallizes in the triclinic crystal system with the space group P-1 and with unit cell parameters a= a = 7.2562(12) Å, b= 8.6896(11) Å, c =11.4407(16) Å ; α = 109.168(7)º, b= 105.648(7)º, γ = 94.4099(8)º and Z = 2. The crystal structure is stabilized by intramolecular C--- H...O hydrogen bonds.