Slow evaporation solution growth technique was adopted to grow good quality urea salicylic acid (USA) single crystals. Single-crystal X-ray diffraction confirmed their cell parameters and corresponding space group. Density functional theory (DFT) calculation was utilized to assess the frontier molecular orbital (FMO) and natural bonding orbitals (NBO) of the USA compound. Theoretically calculated bandgap energy was slightly different from the measured value of 3.49 eV and is utilized in understanding the charge transfer taking place in the molecule. The sample showed a lower cutoff wavelength of 350 nm. FTIR confirmed the presence of relevant functional groups and was found to be thermally stable up to 117 °C. The specific heat capacity of the title compound was found to be 1.28 J/kg/K at 30 °C. Laser damage threshold energy of USA crystal was found to be 1.37 GW/cm2. The electrical behaviour of the crystal was analysed from dielectric measurements. The mechanical stability revealed that the title compound is a soft material. Third-order nonlinear optical property of USA compound was analysed using standard Z-scan technique, which showed better characteristics compared to various reported comparable crystals. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.