Results of dye investigation on museum textiles can serve as a valuable contribution to the determination of age, the revealing of forgeries, the identification of parts belonging together and the choice of appropriate cleaning and conservation methods. The study gives a survey on the analytical methods for identifying natural and synthetic dyes, and on the results of investigations. By evaluating the results of dye investigations on 10 groups of textiles samples of different age and origin, several examples prove the value of dye analysis in the work of curators and restorers. -- AATA