Abstract Single crystal of imidazolium l -tartrate (IMLT) was grown by the Sankaranarayanan-Ramasamy method. The IMLT crystal system and space group were confirmed by single crystal X-ray diffraction (XRD) studies. X-ray Laue back reflection has been used to find out the orientations of the grown crystals. HRXRD studies revealed that the grown crystal shows good crystalline perfection with full-width-at-half-maximum ~23 arc-s. The UV–Vis–NIR studies show that the grown crystal has good transmission in the entire visible region. The refractive index (RI) and relative birefringence were measured for the first time to the best of our knowledge. Refractive index measurement was done by the prism coupling method. The observed variation of RI and birefringence (Δn) along principal directions depict IMLT belongs to a biaxial crystal system. Birefringence interferometry shows that the grown crystal has good refractive index homogeneity. The temperature dependent pyroelectric coefficients of IMLT have been determined. The nonlinear optical (NLO) properties of the IMLT crystal such as absorption coefficient (β), refractive index (n2) and the third order NLO susceptibility (χ(3)) have been analyzed by Z-scan measurement at 632.8 nm wavelength. Laser damage threshold (LDT) value of the SR method grown crystal has been determined at 532 nm by using a nanosecond second harmonic of Nd:YAG laser. Dislocation density of the SR method grown IMLT crystal was calculated by chemical etching studies. The IMLT crystal grown from the SR method has been found to have high laser damage stability, high piezoelectric coefficient and low dislocation density.