An overview of recent research concerning the dyeing of polyester fibers addresses environmentally friendly textile auxiliaries, the fading behavior of azo disperse dyes, improvements in lightfastness, didodecyldimethyl-ammonium bromide as a carrier for disperse dyes, flow injection analysis of disperse dyeing, dyeing polyethlene-2,6-naphthaline dicarboxylate fibers, aftertreatment of disperse dyed polyester with ultraviolet absorbers, and plasticizing and lowering the glass transition temperature of polyester fibers. The addition of ultraviolet absorbing agents can significantly increase the lightfastness of a dye on a fiber as well as prevent the photodegradation of the fiber itself at specific wavelengths of irradiation. The enhanced dyeing properties of disperse dyeing systems using didodecyldimethylammonium bromide as the dye carrier are due to a concentrated dye layer on the fiber surface formed by the strong interaction of acetate fiber and the surfactant. 46 refs.