This paper presents the results of an experimental study on the characteristics of a circular turbulent wall jet growing on a rough boundary, for values of the relative roughness varying from 0.16 to 2.16. The velocity profiles in the central plane as well as the transverse velocity profiles were found to be similar. The length scales in the vertical plane were affected by the boundary roughness whereas the transverse expansion was almost unaffected. The boundary shear stress was affected considerably by the boundary roughness.