Benzimidazolium 3,5-dinitrobenzoate (BDB) was synthesized using benzimidazole and 3,5-dintirobenzoic acid as starting materials. Solubility measurements were performed for the obtained product. Single crystals were grown using acetone as a solvent. The crystal structure of BDB was confirmed using single crystal X-ray diffractions. The compound crystallizes in the monoclinic system with space group P21/c. The transparency of grown crystal in the entire visible region was studied using UV–Vis-NIR spectrum. The photo response property of BDB single crystal was studied using photoconductivity studies. The charge transport mechanism of BDB single crystals were analyzed using dielectric measurement. Hardness studies reveal that BDB crystal shows the reverse indentation size effect. Nd:YAG laser of 532 nm wavelength was used to study the laser damage threshold of the title compound. Z-scan measurement was carried out on the grown BDB single crystal to measure the nonlinear parameters in third order. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.