Experimental investigations of the influence of the collision angle included between the surface of a rotating specimen and a laminar water jet on erosive effect were described. The experimental rig used was presented in Fig. 1 [3]. The peripheral speed of the specimens (Fig.2) was equal to u=85 m/s, the velocity of water jet, having a diameter of 6 mm, was equal to c_*=7.3 m/s. The collision angle β_k was varied within the range 30 ÷ 150^o by changing the tilt of the leading surface of the specimens (Fig. 3). The remaining operating parameters of the rig were not changed. Specimens of PA6 aluminium alloy and 2H13 stainless steel were utilized.