In the production of sugar from sugarcane, a byproduct called molasses is generated, which is used in the production of fuel alcohol this in turn generates a new residue called vinasse. On average, 10 to 15 liters of vinasse are generated by liter of alcohol produced. Vinasse has a high content of organic matter and micronutrients, which pollute the environment because of an inadequate handled. Within these minerals is potassium between 10 and 18 mg/ml, approximately, which limits the use of vinasse as a fertilizer due to the contamination of water sources and soil with this metal and restring its use as component in the formulations of animal food. In consequence, this paper presents the results of the reduction of potassium in distillation vinasses from a sugarmill from the region by a strong cation exchange resin and then, a sulphuric acid solution (4 %) was used as eluent for regenerate the exchange resin. A reduction between 97 – 98 % was obtained from the initial contain of potassium in the vinase and potassium recovery was 99 % as a potassium sulphate solution, which can be used again as liquid fertilizer. Decationized vinasse could be used as organic fertilizer in higher proportion in the sugarcane crops.