A stochastic approach to describe the crystal size distribution dynamics in antisolvent based crystal growth processes is here introduced. Fluctuations in the process dynamics are taken into account by embedding a deterministic model into a Fokker-Planck equation, which describes the evolution in time of the particle size distribution. The deterministic model used in this application is based on the logistic model, which shows to be adequate to suit the dynamics characteristic of the growth process. Validations against experimental data are presented for the NaCl-water-ethanol antisolvent crystallization system in a bench-scale fed-batch crystallization unit. (C) 2009 American Institute of Chemical Engineers AIChE J, 56: 2077-2087, 2010