In the title molecule, C16H13Cl2FN2OS, the dihedral angle between the thiophene and benzene rings is 80.34 (12)°. The pyrazoline ring is in an envelope conformation, and the plane through the four coplanar atoms makes dihedral angles of 85.13 (9) and 6.89 (10)° with the thiophene and benzene rings, respectively. The C and O atoms of the acetyl group are nearly coplanar with the attached pyrazoline ring. In the crystal structure, inversion dimers arise from pairs of intermolecular C—HO hydrogen bonds. A short intermolecular ClS contact of 3.4250 (13) Å is also found.