Ultrasonic (US) energy has revolutionized the dyeing process by introducing the cost and energy effective tools for textile processing. The objective of this research was to use ultrasonic waves as eco-friendly technique to enhance the dyeing process of polyester fabric using disperse red. The fabrics and dye solutions were exposed to ultrasonic waves for 10-60 min. at 60ºC. It was found that 40 min. is the optimal treatment time for fabric to get good colour strength using untreated Disperse Red 343. Whereas good colour strength was obtained by dyeing US treated fabric using non US treated dye solution for 30 min. keeping M:L of 1:60 at pH 10 of dyeing bath. At these conditions not only leveled dyeing was achieved but the good colour fastness characteristics were achieved. It is found that ultrasonic radiation has a great potential to improve the dyeing beahviour of polyester fabric using Disperse Red343 dye.