Abstract Etching has created a great deal of interest amongst researchers and significant experiments have been conducted. Potassium Dihydrogen Phosphate (KDP) is among the most broadly utilized business NLO materials. They are normally utilized for multiplying, significantly increasing and quadrupling of Nd:YAG laser at room temperature. Moreover, they are additionally phenomenal electro precious stones - optic with high electro-optic coefficients, generally utilized as electro-optical modulators, Q-switches, and Pocket cells, and so on KDP was used in the growth of single crystals by gel method. The authors have successfully grown KDP crystals by solution method at ambient temperature. KDP single crystals were etched in an aqueous mixture of fuming nitric acid and tartaric/citric acid along with distilled water. Tetragonal well defined etch pits were observed. The activation energies were calculated using Arrhenius law: - W = A exp (-E/2kT) Where; W is the etch pit width and T the absolute temperature. It was observed that the structure of the etchants pronouncedly affects the enactment vitality. The details will be presented.