Precipitation hardenable aluminum alloys are well-known for their high strength-to-weight ratio, good thermal stability, electrical conductivity, and low cost. Equal channel angular pressing (ECAP) is proven to further improve the mechanical properties of metallic alloys through microstructure modification. In this work, ECAP of a recently developed, precipitation hardenable, cast Al–Er–Sc–Zr–V–Si alloy in peak-aged condition by route 4Bc was carried out to create an alloy with ultra-fine grain structure. The combined effect of grain refinement and precipitation on the tensile behavior and thermal stability of the ECAPed alloy is reported here. Improvement in yield strength and lack of strain hardening in ECAPed alloy were as expected. Microhardness contour plots with a narrower spread indicated enhancement in microstructural homogeneity after four ECAP passes as compared to the peak-aged condition. The variations in microhardness after annealing heat treatments at different temperatures highlighted the important role precipitates play in maintaining microstructure stability up to 250 °C in the ECAPed material.