Hypostoichiometric Ni3Al alloys of composition 76.2 Ni:23.8 Al containing impurity levels of boron and hafnium (supplied by Oak Ridge National Laboratory) were either cold rolled or pressed. Rolled and pressed samples were deformed by 20% and 10% thickness reductions, respectively. Samples were annealed isochronally at approximately 50ºC intervals up to 1050ºC. Two major annealing stages were apparent in all three alloys studied. These could be attributed to vacancy migration to sinks and annealingof dislocations and(or) recrystallization. The onset of vacancy migration occurred at approximately 200ºC in all three alloys. Annealing of dislocations started at 650ºC to 700ºC and was complete at 1000ºC for alloys which contained boron and or hafnium impurities. In the pure alloy the onset of dislocation annealing occurred at 800ºC and was incomplete at the highest (1050ºC) annealing temperatures reached.