Arginine in grape juice can be metabolized by wine yeasts and malolactic bacteria to precursors of ethyl carbamate, a known carcinogen. The aim of this study was to develop a simple, fast and accurate method for determining arginine in grape juice with Sakaguchi reaction following the separation of arginine with Amberlite IR120 strong cation-exchange resin. Measurement was done under optimized conditions as follows: sample (mg) to cation-exchange resin (g) ratio of 0.683, sample pH 2.0, sample flow rate 0.5 mL/min, use of distilled water rinsing to avoid interference of other compounds adsorbed on the resin, and elution with 1 mol/L of NaOH solution. This method can be applied in a quick and accurate quantification of arginine in grape juice for controlling the ethyl carbamate level in wine.