Pentaerythritol crystals were grown by batch desupersaturation of a seeded solution of the purified material in a draft tube crystalliser of 0.25 x 10(-3) m(3) capacity. First and second order rate constants in the high and low supersaturation regions respectively were correlated in terms of the activation energies. The activation energies were found to be 42 and 64 kJ mol(-1) respectively with the driving force expressed as relative supersaturation. The very high value for the activation energy in what is normally considered to be the diffusion zone suggests that some impurity was still present. (C) 2008 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.