The dipleg can generally operate in three basic flow regimes; packed-bed, fluidized-bed flow and a dilute flow called streaming flow. The most common perception of an overflow dipleg is that it consists of a fluidized dense phase at the bottom and a dilute phase in the upper part. This paper presents the tomographic images obtained at three locations along the dipleg. These show the effects of solids mass fluxes and the backpressure on the character of solids distribution along the pipe cross-section. The radial profiles of average solids distribution are compared with the literature data. (C)2000 Elsevier Science S.A. All rights reserved.