It is well established that superplasticity requires a small grain size and therefore there is an interest in developing processing methods having the capability of reducing the grain size below that generally produced in conventional thermo-mechanical processing. Experiments were conducted on a superplastic Zn-22%Al eutectoid alloy where the material was subjected to equal-channel angular pressing (ECAP) through 4, 8 or 12 passes at a temperature of 373 K. It is shown that this processing procedure leads to additional grain refinement such that the grain size was reduced from an initial value of similar to1.8 mum to values as low as similar to0.6 mum. Tensile testing after ECA pressing revealed a significant enhancement of the superplastic properties including both increases in the total elongations to failure and the occurrence of these high elongations at very rapid strain rates. Elongations were achieved of up to >2380% at a strain rate of 1 s(-1). The results suggest that ECAP may be a very useful procedure for attaining superplasticity at high strain rates in commercial alloys.