Ascorbic acid, a water-soluble vitamin, is the most common electroactive biological compound found in some fruit species. The electrochemical oxidation of ascorbic acid was investigated at glassy carbon electrode in various aqueous solutions in the pH range of 0.64-10.15 (in Britton-Robinson, acetate, phosphate buffers and 0.5 mol L-1 sulphuric acid solutions) by cyclic (CV) and differential pulse (DPV) voltammetry. For the quantitative purposes, a very well-resolved diffusion-controlled voltammetric peak was obtained in 0.2 mol L-1 acetate buffer (pH 3.49) at 0.342 V by DPV technique. The linear response was obtained in the concentration range of 6x10(-6)-8x10(-4) mol L-1 with a detection limit (LOD) of 5.17x10(-7) and quantitative limit (LOQ) of 1.72x10(-6) mol L-1. Ascorbic acid in pharmaceutical dosage forms and some fruit juices were determined by DPV. The reliability of the proposed voltammetric technique was established by recovery studies.