An Al-4Mg-0.3Sc alloy, aged at 280°C for 8 hours and cold rolled to a 70% reduction, exhibited dynamic recrystallization during superplastic forming at 460°C and at a strain rate of 10−3sec−1. To understand the progression of recrystallization during forming, specimens were deformed under these same conditions to 0.1, 0.2, 0.4 and 0.8 true strain and studied postmortem using optical microscopy, transmission electron microscopy and orientation imaging microscopy. The microstructural evolution that occurred between each strain state was directly observed during deformation experiments at a nominal temperature of 460°C in the transmission electron microscope. These in-situ experiments showed the migration, coalescence, disintegration and annihilation of subboundaries. This combination of post-mortem analysis of specimens strained in bulk with real time observations made during these in-situ experiments allows the mechanisms operating during dynamic continuous recrystallization to be ascertained.