In the present study, granular modelling with an interstitial power-law fluid was used to simulate the filling process in powder injection moulding (PIM). The granular model enables direct prediction of the density distribution. The feedstock, consisting of stainless steel powder and a multicomponent binder system, was injected in two moulds with designed features to verify the simulation results. The effects of the moulding parameters on the homogeneity of the powder particle distribution were investigated. The experimental results agreed well with the predictions. The results indicated that the granular model presented herein could be used for mould design and the determination of injection parameters. (C) 2015 Elsevier B.V. All rights reserved.