The present article focuses on mechanism of delamination and kerf geometry in abrasive water jet machining of carbon epoxy composite. In the present study, four process parameters of abrasive water jet machining namely hydraulic pressure, traverse rate, stand-off distance, and abrasive mass flow rate are considered. The experiments are performed on the basis of response surface methodology as a statistical design of experiment approach. Delamination in machined samples is observed by using scanning electron microscope. Analysis of variance is performed in order to investigate the influence of process parameters on delamination, kerf taper ratio, and kerf top width. It is found that delamination decreases with increase in pressure and abrasive mass flow rate and decrease in stand-off distance and traverse rate. Kerf taper ratio decreases with increase in pressure and decrease in traverse rate and stand-off distance. Kerf top width decreases with decrease in stand-off distance and increase in traverse rate. Based on analysis, mathematical models are developed to predict the maximum delamination length, kerf taper ratio, and kerf top width. Further, a multi-response optimization is performed on the basis of desirability function to minimize delamination, kerf taper ratio, and kerf top width.