The aim of this work was to evaluate the influence of the operating conditions on the coating efficiency for urea coated in a spouted bed and to analyse the decrease of nitrogen volatilisation for the coated urea. Coating efficiencies in the range (from 44.24% to 73.7%) were obtained for the different process conditions applied. Volatilisation analyses showed that the polymer film coating provided a decrease of the nitrogen loss in the range from 3% to 57%. The use of vinasse in substitution to the water in the coating suspension was tested for the optimum process conditions. (c) 2012 Canadian Society for Chemical Engineering