Rigid Polyvinyl Chloride (RPVC) fittings are fast replacing the conventional metallic fittings in many applications such as agriculture, irrigation, sanitation,   electrical conduits, portable water, chemical processing plants etc., because of light weight and good chemical resistant properties. Hence proper design of rigid PVC is crucial for efficient and economical production. In the present work, the rigid PVC elbow with sharp corner is considered for analysis. In elbow, the stress concentration occurs at the corners. In this work the elbow with sharp corner has been modeled   using PRO-E WILDFIRE and also various elbow models have been modeled by varying the parameters such as wall thickness at curvature of elbow, wall thickness at socket end and geometry at junction of elbow. All the models have been subjected to 0.6MPa pressure and analyzed for maximum stresses using ANSYS 10.0.  The multiple regression model has been developed for the prediction of maximum stress in terms of the above parameters. The adequacy of the developed model is verified by using coefficient of determination and analyzed using analysis of variance (ANOVA). An attempt also has been made to optimize the maximum stress using genetic algorithm.