The dispersion of an insoluble dye powder in water or in some other liquid medium proceeds in three distinct stages: Wetting of the powder by the liquid, breaking up the clusters into primary particles and stabilization of the dispersion. These three stages are very important in both for the appearance of the disperse dyes as well as for their application according to the different dyeing processes.[22] In this article, stability of dispersions containing Irgasol DAM and Asutol 644 and the effects of auxiliaries on the prepared dispersions in dyeing of polyester fabrics with disperse dyes were studied. For this purpose, a disperse dye applied to polyester fabrics at different concentrations (0.1%, 0.4%, 1%, 2%, and 4%) in high temperature method (HT). After the dyeing process, the stability of prepared dispersions was evaluated by turbidity measurements and leveling properties of dyed fabrics was assessed visually. The results obtained from turbidity measurements show that the wastewater related to Irgasol DAM and Asutol 644 containing the wetting agent and dextrin has more turbidity, therefore, they have the more stability in the dyeing process (Figure 5). The visual observations indicate that the wastewaters from cells with lower concentrations (Cdye ¼ 1% and 2%) are almost clear, but increasing the concentration (Cdye ¼ 4%) causes more turbidity in the wastewaters. The results display that increasing the concentration (Cdye ¼ 4%) results in the presence of dye dispersed particles in the wastewater. Figure 5 represents that the wastewaters containing wetting agents and b-cyclodextrin have the lower deposited dye because wetting agents and b-cyclodextrin cause the more solubility of the dye in water. Increasing the dye adsorption on polyester fabrics resulted in increased dye uptakes and improved the stability of prepared dispersions.