A simplified mold filling simulation program was developed to model a resin transfer molding (RTM) manufacturing setup currently being used at Virginia Polytechnic Institute and State University. This program was designed to estimate the effects of process variables on mold filling time. The mold filling process was assumed to follow Darcy's Law, and with one dimensional simplification, closed form solutions were derived for constant flow rate and constant pressure injections. The program was also designed to incorporate the cure kinetics and viscosity submodels of the resin system. These models were used to determine flow front position, degree of cure, inlet pressure, and temperature as a function of time. Compared to more complicated models, the model served as simple tool to aid in use of the RTM process. The model, however, was found to under predict the infiltration times. Probable causes for this difference were postulated.