Abstract: The present invention is an improvement in radial diffusers employed in a turbine engine having a centrifugal compressor. The walls of the diffuser define at least one flow passage through the diffuser having a first portion with a first cross-sectional area and a second portion having a larger, second cross-sectional area. The first wall section is spaced apart from the second wall section so as to define a bleed aperture therebetween. A vortex fence extends outwardly from the wall surface at the leading edge of the second wall portion. Preferably, the bleed aperture and the vortex fence are disposed on the suction surface of each vane in a vaned radial diffuser.