Urea release from a scoop of coated beads in a given volume of a well stirred liquid has been investigated analytically and experimentally. A method for determining the fractional cumulative release and fractional release rate curves for the scoop without knowing particle number and radii is presented. The representative D/K-b for a scoop of urea beads spray coated with ethyl cellulose is near 3.5 x 10(-8) cm(2)/s, and that with cellulose acetate phthalate is near 7 x 10(-8) cm(2)/s. (C) 2007 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.