A uniform and eco-friendly heating source, ultraviolet radiation has auspiciously improved the disperse dyeing of polyester fabrics. For our current study we used disperse yellow 211 (DY 211) to dye polyester fabric under the influence of ultraviolet treatment. Both the fabric and dye solution were UV-treated for 15-60 min and dyed under variable conditions. We found that ultraviolet-treated polyester (RP) for 30 min. gives good color strength and darker shades at 70ºC using 70 mL of un-irradiated dye solution (NRS) of pH 8 in the presence of 2% of dispersant. While for the dye bath of pH 11, irradiated polyester (RP) for 45 min. using 90 mL irradiated dye solution (RS) gives good color strength and darker shades at 100°C in the presence of 1% of dispersant. ISO standards for fastness revealed good-to-excellent ratings for different shades dyed under optimal conditions. Ultraviolet treatment not only reduced the time, labor, and money, but also improved color characteristics.