In this paper, the process of seeded granulation in a high shear mixer is simulated by the discrete element method (DEM). A 5 litre Cyclomix granulator manufactured by Hosokawa Micron B.V. was simulated at different impeller rotational speeds. It has been observed that the seeded granules form by a continuous growth and reduction in size during the granulation process. Quantitative analysis shows that in general a higher number of seeded granules form at lower impeller rotational speeds; however it is found that for all the seeded granules the seed surface coverage by fines is from 5% to 60%. Further analyses revealed that seeded granules with the seed surface coverage higher than 50% are more frequently formed at high impeller rotational speeds. The work demonstrates the capability of DEM for modelling granulation processes, as a tool to explore the underlying mechanisms of granulation in general and seeded granulation in particular. (C) 2012 Elsevier B.V. All rights reserved.