The effect of fine, non-shearable, dispersoids on the grain refinement of aluminium alloys, severely deformed by ECAE, has been studied using a model Al-0.2%Sc alloy, during deformation by Routes A and BC (+90degrees rotation) using a 120°, or 90°, die. The microstructure in the dispersoid-containing alloy was compared to a single-phase alloy using high resolution EBSD analysis. With Route A the presence of fine dispersoids was found to significantly retard the development of new high-angle grain boundaries and the formation of a fine grain structure, by homogenising slip and inhibiting microshear bands. This difference was greatly enhanced, using Route BC. Similar results were obtained with the two die angles, but with Route A refinement tended to be slightly less effective when using the 90° die.