Experiments were conducted on a commercial aluminum Al-2004 alloy known as Supral 100 and containing 6% Cu and 0.4% Zr. This material was subjected to Equal-Channel Angular Pressing (ECAP) over a range of experimental conditions and the mechanical properties of the as-pressed samples were determined using standard tensile testing. Samples were pulled to failure and the level of internal cavitation was then recorded quantitatively using metallographic techniques. The results show this alloy exhibits good superplastic properties after ECAP with total tensile elongations up to >1000%. As in conventional superplasticity, there is the development of extensive internal cavitation in this alloy in the as-pressed condition. Measurements are reported for the average sizes and shapes of these cavities.