Injection molding is a flexible production method for manufacturing polymer products, but introduces residual stresses. This study employs the incremental hole-drilling method to measure the residual stresses in injection molded parts. To compare the results, the layer-removal method is utilized for measurement of residual stresses. A commercial software, Moldflow, is used for prediction of residual stresses in molded plastic parts. Results obtained by experiments and Moldflow analysis are compared. The incremental hole-drilling method is applicable to determination of the residual stresses in complex geometries and can be used as an adoptable technique for measurement of the residual stress in polymeric materials.