Good-quality single crystals of an efficient nonlinear optical (NLO) chalcone derivative 1-(5-chlorothiophen-2-yl)-3-(2,3-dichlorophenyl)prop-2-en-1-one (CTDCP) which meets many of the physicochemical requirements like transparency in the entire visible region, thermal stability, mechanical hardness have been achieved. The crystal belongs to orthorhombic system with the centrosymmetric space group Pbca. The third-order NLO properties were investigated using a single beam Z-scan technique with nanosecond laser pulses at 532 nm. The nonlinear refractive index is found to be of the order of 10(-11) cm(2)/W. The magnitude of third-order susceptibility is of the order of 10(-13) esu. The compound exhibits good optical limiting at 532 nm. The mechanical property of the crystals showed load dependent hardness. The static and frequency dependent molecular hyperpolarizabilities were computed using MOPAC 2012. Thermal study confirms that the crystal is dimensionally stable up to 179 degrees C. The influence of direction of charge transfer on the nonlinearity of the molecule has been discussed in detail.