2-Ammoniumbenzamide trioxonitrate crystals (2-ABN) were prepared and grown at room temperature. This compound crystallizes in the orthorhombic system with non-centrosymmetric P2 1 2 1 2 1 space group. The unit cell dimensions are a = 4.8900(9) Å, b = 9.5541(19) Å, c = 18.961(4) Å with V = 885.8(3) Å 3 and Z = 4. The structure refined to a reliability R factor of 4.34%. The 2-ABN structure consists of 2-ammoniumbenzamide cations (C 7 H 9 N 2 O +) and trioxonitrate anions (NO − 3) interconnected by hydrogen bonds originating from amine group donors [N−H • • • O], so as to build a three-dimensional arrangement. The crystal structure, the thermal behaviour and the IR spectroscopic studies were discussed. The optical studies reveal that the 2-ABN crystal could be a good candidate for nonlinear optical devices. The dielectric properties, real and imaginary dielectric permittivities (ε and ε) and dielectric loss tangent (tan (δ)), of the crystal at different frequencies of the applied field are reported.