In this study, ultrasonic-assisted drilling was performed on different heat-treated (T6, T1) AA6061 to investigate the effects of cutting parameters on forces, surface roughness, and tool wear. TiN-coated and uncoated HSS-G drill bits were used in the experiments. The results obtained in the experiments were evaluated according to the general full factorial design and the effect graphs of different drilling parameters were generated. In addition, ANOVA tables were created to evaluate the results. SEM and OM micrographs were used to investigate the tool wear and chip formation. Finally, a multi-response optimization was performed to optimize drilling parameters for minimum cutting force and surface roughness. According to, optimum drilling parameters were determined as AA6061-T6 for material, uncoated HSS-G for a drill bit, 1520 rpm for spindle speed, and highest ultrasonic vibration frequency at 22.5 kHz. In addition, it was observed that ultrasonic vibration has the effect of reducing built-up edge formation on the drill bit. (C) 2020 CIRP.