The shrinkage and warpage behavior of injection molded parts is very complex. By using a new measuring method it was shown for the first time that the warpage can be classified as warping and distortion. In general, warpage can only be reduced substantially by a sufficiently high volumetric compensation in the holding pressure phase. Residual stress measurements show, deviating from the literature, that flow induced residual stresses can also cause compressive stresses in the part core due to pressure holding effects.