In order to save resources and energy in textile washing, ultrasound was applied as a mechanical action for soil removal. Plain-woven polyester, cotton and polyester/cotton (65/35) fabrics were soiled with oleic acid, carbon black or oleic acid/carbon black mixture as a model soil. The artificially soiled fabrics were washed in an aqueous anionic surfactant solution with applying 38 kHz ultrasound. The detergency determined by the surface reflectance method rapidly increased with time and attained almost constant within a few minutes. The detergency after 1 min washing was found to increase with increasing electric power consumption of ultrasound. The washing tests were repeated ten times in the same wash bath to save water and detergent and the obtained detergency did not change significantly. The detergency of oleic acid and oleic acid/carbon black mixture after washing with 420W ultrasound for 1 min was comparable to that with Wascator, a horizontal axis drum type washer. Furthermore, the mechanical action values obtained for ultrasonic washing were much smaller than those for Wascator, indicating that the fabric damage can be prevented by applying ultrasound to textile washing.