The possibility of reducing the dyeing temperature of wool fabrics by means of an oxygen low-temperature plasma etching pretreatment at different discharge powers was investigated. We dyed fabrics at 98, 85, and 80 degrees C, replicating the dyeing recipe and process of a dyeing mill on a laboratory-scale machine. The plasma treatment modified the surface morphology and greatly increased the wettability and initial dyeing rate and shortened the half-dyeing time, improving the diffusion of the dyes into the fibers at lower dyeing temperatures. In particular, the pretreatment allowed us to dye the wool fabrics at 85 degrees C without affecting their dyeing performances in terms of final bath exhaustion and colorfastnesses. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 1173-1183, 2010