Organic crystal of 2-aminopyridinium diphenylacetate diphenylaetic acid with dimensions 22 × 13 × 11 mm3 was grown by slow cooling technique. The structural confirmation has been done using single crystal X-ray diffraction study. The title compound crystallizes in the monoclinic crystal system with noncentrosymmetric space group P21. The C-H-O, N-H-O type of packing for the title compound has been reported. Optical transmittance shows a wide transparency in the visible region with lower cutoff wavelength at 349 nm. The four independent tensor coefficients of dielectric permittivity were found to be ε11 = 12.16, ε22 = 10.68, ε33 = 11.90 and ε13 = −4.24 from the dielectric measurements. The thermal stability of the 2APD compound was found to be 128˚C assessed by TG-DTA analyses. The particle size SHG of the 2APD reveals that it is a phase-matchable NLO crystal. © 2018