Abrasive water jet cutting (AWJC) is one of the widely used non-conventional techniques for cutting difficult-to-cut materials like composites, super alloys and ceramics. However, while conducting initial trials the inability of the jet to cut through the workpiece is a major problem particularly in thicker materials. Therefore an accurate prediction of depth of cut (DOC) is absolutely necessary to achieve through cuts and more so to minimize delamination in polymer matrix composites. In this paper, a semi-empirical model is developed using non-linear regression analysis for prediction of DOC in AWJC of thick Kevlar-epoxy composites. Further, the model is verified by conducting experiments within the investigated range of process parameters and a good agreement is obtained between the two.