Detergency of textiles by low-water laundering was assessed with a drum-type washing machine called a Wascator. An artificially soiled cotton fabric (Sentaku Kagaku Kyoukai) and three mechanical action fabrics (WAT cloth, Poka-Dot®306 and MA test piece) were attached to cotton ( 920×920 mm² ) and polyester ( 200×200 mm² ) load ballasts and then washed in aqueous alkaline detergent solution with a different bath ratio. The washing procedures used were normal, gentle and hand wash in accordance with ISO 6330. At the extremely low bath ratio of 1:3, both detergency, D, and the mechanical action value, ΔL^*, decreased for all washing procedures. The magnitude and the deviation of D and ΔL^* were dependent on the load ballasts used, indicating that soil removal was prevented and that uneven washing was promoted for large clothes. The relation between D and ΔL^* for all experimental data was plotted on almost the same line in the high ΔL^* region. In the low ΔL^* region, the relation was dependent on the bath ratio, i.e. detergent bulk concentration. For low-water laundering, it was suggested that the detergency performance decreased as a result of the reductions of the mechanical action and detergent bulk concentration.