Surface finish and part deposition time are two important concerns in rapid prototyping (RP). These two concerns contradict with each other. Generally, a compromise is made between the two aspects pertaining to model building in RP. A compromise between these two contradicting issues can be achieved by using an adaptive slicing scheme; however, selection of a proper part deposition orientation will further provide an improved solution. Present work is an attempt towards obtaining an optimum part deposition orientation for fused deposition modeling process for enhancing part surface finish and reducing build time. Models for evaluation of average part surface roughness and build time are developed. A real coded genetic algorithm is used to obtain the optimum solution. Predictions of the present metzhodology are in good agreement with the result published earlier. Proposed methodology can be used to obtain the optimum deposition orientation for any type of component without selecting the preferred orientations. © 2003 Elsevier Ltd. All rights reserved.