In abrasive waterjet (AWJ) cutting, the vertical cutting force is much lower compared to other conventional machining processes. The present paper describes a model that predicts the vertical cutting force in AWJ using waterjet pressure. The experimental results were found in good agreement with the theoretical vertical cutting force to a reasonable degree of accuracy. The results show that as pressure increases, the vertical cutting force increases while both the traverse rate and the abrasive flow rate have a slight effect on the vertical force over a wide range of experimental values.