A Monte Carlo-based algorithm for simulating the mass crystallisation process in a continuous adiabatic MSMPR crystallizer was presented. The algorithm is based on accurate, reciprocal interrelations among mass, heat, population balances and kinetic (nucleation, crystal growth) equations. The algorithm was successfully used to simulate the mass crystallisation process of the two inorganic salts - KNO3 and CUSO4.5H(2)O - where DeltaL McCabe's rule is fulfilled. The obtained results reflect physical nature of the mass crystallisation process correctly reproducing the periodical fluctuations of selected process parameters. (C) 2004 Elsevier B.V. All rights reserved.