KDP single crystal was successfully grown in second harmonic direction (SHD) in aqueous solution by modified Sankaranarayanan–Ramasamy method. Apart from usual characterization techniques employed to study the physical properties of the grown crystal such as X-ray diffraction, Fourier transform infrared, UV–Vis spectroscopy techniques and Vicker,s microhardness measurement, the grown crystal was subjected to a Nd:YAG laser (1064 nm) and green color laser light (532 nm) was observed. UV–Vis analysis of second harmonic and directions showed that the transmission of the later one was higher. Vicker’s microhardness studies of direction showed that it is harder than SHD.