Purpose The aim of this paper is to optimize the machining parameters to obtain the smallest average surface roughness values during drilling of the carbon fiber-reinforced polymer (CFRP) composite material with abrasive water jet (AWJ) and analyze the damage of the delamination. Design/methodology/approach CFRP composite material had been fabricated having fiber orientations frequently used in the aerospace industry (0 degrees/45 degrees/90 degrees/-45 degrees). Three different stand-off distances (1, 2 and 3 mm), three different water pressures (1,800, 2,800 and 3,800 bar) and three different hole diameters (4, 8 and 12 mm) were selected as processing parameters. The average surface roughness values were obtained, and delamination damage was then analyzed using Taguchi optimization. Drilling experiments were performed using the Taguchi L-27 orthogonal array via Minitab 17 software. The signal/noise ratio was taken into account in the evaluation of the test results. Using the Taguchi method, the control factors giving the mean surface roughness values were determined. Analysis of variance was performed using the experimental results, and the effect levels of the control factors on the average surface roughness were found. Findings It was found that water pressure and hole diameter had a higher effect on average surface roughness, while water pressure and stand-off distance were effective on delamination. Originality/value The novel approach is to reduce cost and spent time using Taguchi optimization as a result of AWJ drilling the material in this fiber orientation ([0 degrees/45 degrees/90 degrees/-45 degrees](s), which is often used in the aerospace industry).