Viscous flow or the resin in nano-imprinting lithography has been investigated. Flow behavior of the thermoplastic polymer was analyzed experimentally as well as numerically. Effects of process variables such as the temperature and the pressure and the stamp geometry on the filling pattern were studied. In order to observe the effect of stamp geometry.. three different types of geometries were considered. Experiments were performed using polymethylmethacrylate (PMMA) sheets. Filled patterns were observed using a scanning electron microscopy (SEM). Fixed grid method along with the finite element method was used for numerical analysis. Numerical results exhibited a similar tendency as the experimental observation. (C) 2007 Elsevier B.V. All rights reserved.