Effect of thermomechanical processing including equal-channel angular pressing (ECAP), solution treatment, water quenching and artificial aging on microstructure and mechanical properties of an Al-Cui-Mg-Ag-Sc alloy was examined. It was shown that ECAP provides extensive grain refinement. However, extensive grain growth occurs under subsequent solution treatment resulting in coarse grained structure. It was showed that ECAP following water quenching provides a minor increase in strength of the alloy. No effect of ECAP on the precipitation sequence under ageing was found. -phase precipitating under ageing condition is in dominant. As a result, the alloy exhibits high yield stress up to a temperature of 175oC. Conditions for attaining increased strength in the alloy by ECAP processing are discussed.