A transparent uniaxial semi-organic sodium acid phthalate (NaAP) single crystal having dimension of 36 mm length and 20 mm diameter was successfully grown by Sankaranarayanan-Ramasamy (SR) method for the first time in the literature. The solubility and the nucleation of the material for different temperatures have been studied. The metastable zone width for NaAP has been investigated. The grown crystals were characterized by UV-vis and microhardness studies. The structural perfection of the grown crystal has been analyzed by high-resolution X-ray diffraction (HRXRD) rocking curve measurements. The range and percentage of optical transmission are ascertained by recording UV-vis spectrum. Microhardness measurements reveal the mechanical strength of the grown ingot. (C) 2009 Elsevier B.V. All rights reserved.