In this work, to analyze a type of rapid prototyping technique, a numerical model was developed that was able to simulate the heat transfer at thermosensitive polymeric material during cure by laser irradiation. The analysis was carried out as a transient thermal problem using the general-purpose finite element software ANSYS. The technique analyzed was thermal stereolithography, which uses a CO2 laser beam to cure (solidify) thermosensitive liquid resins in a selective way to produce three-dimensional parts. In this numerical analysis, the temperature distribution at thermoset material heated by a laser irradiation and its thermal properties are investigated. This resin is a high-viscosity sample composed of epoxy resin, diethylene-triamine, and silica powder, which become highly crosslinked when irradiated by infrared laser. The localized curing becomes critical when the amount of silica and laser parameters are not appropriate. Bearing this in mind, this work intends, by applying the numerical method developed, to analyze the thermal behavior of resins in function of amount of silica and the laser radiation conditions, so that it is possible to have a knowledge on these variables so as to achieve a product with the required specifications. (c) 2006 Wiley Periodicals, Inc.