The fretting wear characteristics of a low-carbon steel (AISI 1018) at a 20 kHz ultrasonic testing frequency have been studied. The tests show that after an initial running-in period there exists a linear relationship between wear volume and number of cycles. Fretting wear is also found to increase exponentially with load and amplitude, the effect of load being the strongest within the studied range. By comparing obtained wear data and observed wear mechanism with results in literature from low-frequency fretting of the same material, it is found that a similar behavior is obtained in spite of the large difference in frequency. These results suggest that ultrasonic fretting can be utilized as an accelerated method for fretting wear testing.