Stereolithography (SL) is one of the popular RP processes used for rapid tooling applications.The contribution of three parameters namely layer thickness, post-curing time andorientation are the most significant to the strength of SL product. In this paper, an attempthas been made to identify the process parameters that influence on the strength of partsmade with CIBA TOOL 5530 in SL 5000 machine, one of the processes used for rapid toolingand optimize the parameter levels. Addition to the above, a process model (empiricalrelationship/regression model) between part strength (tensile, impact, flexural) and the above-mentioned process parameters (layer thickness, post-curing time and orientation)has been developed. The process model obtained by the empirical relation can predict howmuch strength can be achieved for a given set of the process parameters, thus providing priorknowledge of part strength before actually making a SL part. The process model is able toshow the dependency of strength on process parameters, which is very useful informationfor machine designers as well as RP machine users.