High-pressure waterjets have emerged as a viable method for surface texturing, cleaning, and peening of metallic materials. As the material advancements continue, research into alternate surface processing methods must strive to keep pace. One material in particular that has experienced an increase in use in the biomedical and aerospace industries is titanium—due largely to its high strength to weight ratio and corrosion resistance. In this paper, surface preparation of a titanium alloy using waterjet and the water-air jet nozzles at pressures up to 600 MPa was evaluated. A parametric study was performed based on the supply pressure, standoff distance, traverse rate, and applied air flow rate. An analysis of variance was performed on the resulting experimental set to identify the key parameters contributing to the material erosion rates and resulting surface roughness parameters. The supply pressure was found to be the primary contributor to the erosive characteristics of the waterjet followed by the traverse rate. These parameters together govern the total energy per unit area transferred to the workpiece.