The use of the declination angle for a prediction and control of the abrasive water jet cutting quality is presented in the paper. The term declination angle is defined and the method for its measurement is proposed. The relationship between the declination angle and cutting wall quality is explained in the theory resulting from former conclusions of Hashish, Zeng and Kim, Hlaváč and others. Experiments proving the theoretical base were performed. The values of the limit traverse speeds predicted from the theoretical equations were compared with values experimentally determined on selected samples. The data calculated from the theoretical models predicting the appearance of the striations on the cutting walls by cutting head tilting are compared with experiments as well.