This investigation addressed the role of nonionic surfactants on the sorption of C.I. Reactive Blue 217 by cellulose fibres, focusing on the influence of the surfactant concentration and type on the spectroscopic properties of this dye. It was found that surfactants in dyeing baths change the spectroscopic properties of dye solutions, resulting in the decomposition of aggregates and agglomerates to form a surfactant-dye complex. The surfactants in baths counteract the aggregating action of sodium chloride. The performed studies concerned the sorption kinetics of dye from dyeing baths containing various surfactants and their influence on the exhaustion coefficients of the dye. Changes in the electrokinetic potential of the dyeing bath were also examined. It was found that nonionic surfactants retard the sorption processes of dye from the dyeing bath, improving dyeing quality.