A finite element (FEM) approach using an implicit time integration algorithm has been developed to simulate isothermal resin transfer molding process. The finite element formulation is based on the concept of partial saturation at the flow front. The discretized equation is essentially the same as is obtained by a finite element/ control volume formulation. The FEM approach is easier to implement for different types of elements. Unlike the explicit time integration schemes, the proposed implicit algorithm uses fixed time steps and allows the flow to advance farther than a layer of flow front elements in a single time step. The resulting code RTMSIM has been validated by comparing its predictions with closed-form solutions for flat plates. A wicking analysis is provided to show the code's ability to deal with the effect of capillary pressure. Several other simulations are provided to demonstrate the accuracy and efficiency of the code. (C) 1998 Published by Elsevier Science Limited. All rights reserved.