L-Histidine tetrafluoroborate (L-HFB) is a highly transparent monoclinic crystal with favourable properties of efficient frequency conversion. Single crystals have been grown successfully by a slow evaporation method. The solubility of the L-HFB crystal is very high in water when compared to other solvents like acetone or methanol. In this study, L-HFB crystals were grown from aqueous solution. The grown crystals have been subjected to X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), second harmonic generation and ultraviolet-visible spectral analyses. Thermogravimetric and differential scanning calorimetry analyses have been performed to study the thermal stability of the crystal. Capacitance and dielectric loss measurements were carried out and the dielectric constant was calculated at room temperature in the frequency range 1 kHz-40 MHz. The dielectric constant at room temperature remains constant for the entire frequency range. (C) 2004 Elsevier B.V. All rights reserved.