Computer simulations of ice behaviour in the marginal ice zone (MIZ) are described. Two cases were studied, a constant velocity wind blowing at certain angle with respect to the coast in what can be considered a simplified MIZ problem, and a vortex-wind force field. The viscous-plastic approach of Hibler has been used to model the ice rheology. We study the effects of adopting two different rheologies: cavitating fluid and Mohr-Coulomb. The introduction of shear strength effects through a Mohr-Coulomb yield criterion plays an important role in determining ice drift velocities in the MIZ. The effects that ice floe collisions can have in determining the ice rheological behavior have been tested by using discrete-particle simulations. In order to do so, simulations for the MIZ were performed using different mean floe sizes, as well as different MIZ widths and wind conditions. The predictions of the discrete-particle simulations are in general agreement with the results obtained by using the Mohr-Coulomb rheology in the viscous-plastic model. The continuum models were solved by using a fully Lagrangian method known as smoothed particle hydrodynamics (SPH). The method has the advantage of the Lagrangian techniques in avoiding problems of numerical diffusion. An additional advantage of SPH in comparison with classical Lagrangian approaches is that SPH does not need grids, and this makes it well suited to handle problems of large deformations.¿ 1997 American Geophysical Union