A new procedure to design the multi-kink axial radial diffuser of a steam turbine exhaust hood has been developed. In phase 1, the sensitivity of the parameters, which define the exhaust hood outer boundary-the end-wall distance from the turbine exit and the outer casing diameter and the effect of having a volute casing as well have been studied to arrive at a better design envelope. For this design envelope, design optimization of a multi-kink axial radial diffuser has been carried out using the Design of Experiments in phase 2. The compressible 3D Navier-Stokes equations with standard k-ε turbulence model has been solved. The results reveal that there exists a minimum end-wall distance below, which flow separations occur. Besides the end-wall distance, the gap between the outlet of the diffuser and the outer casing is found to be another significant parameter in influencing the performance. A right combination of diffuser tip geometrical parameters has been arrived at to produce an enhanced performance. © School of Engineering, Taylor’s University.