Drum dyeing is the application of dyestuffs to the leather by the immersion of leather in drums which is tumbled. This process allows the leather to be fully penetrated by dyeing. The purpose in drum dyeing is to achieve is the desired colour to appear level and uniform through out in the same drum. In conventional leather processing, the diffusion of chemicals through the pores of the skin/hide is achieved by the mechanical agitation caused by the paddle or drumming action. In this work, the use of power ultrasound in the dyeing of leather has been studied with the aim to improve the exhaustion of dye for a given processing time, to reduce the dyeing time and to improve the quality of dyed leather.