Abstract The growth of a new metal-organic crystal, bismuth thiourea chloride (BTC), is reported. The optimum conditions for growing bulk BTC single crystals in gel were investigated. The crystal grown was characterized by chemical analysis, energy dispersive X-ray (EDX), X-ray diffraction (XRD), and infrared (IR) techniques. BTC crystallizes in the hexgonal system with space group P3. The dielectric constant and refractive indices of the BTC single crystal were determined.