Spontaneous densification of a particulate mass during sintering is driven by the thermodynamically unstable state of the system. Thermodynamic or sintering stresses are induced by the current microstructural state of the system and can be quantified within the context of a continuum theory for sintering granular materials [1]. Using this theory, numerical simulations of the densification process using finite elements have been made. An interesting consequence of the simulations is the prediction of the formation of relatively low density regions caused by initial density variations. Such low density regions are likely sources of defects such as crack initiation sites.