The recrystallization behaviour of an Al–1% Mg alloy has been investigated following hot deformation under varying strain-rate conditions. Significant differences in recrystallized grain size and recrystallization kinetics are observed following a decreasing strain rate, as compared with constant strain-rate tests. These differences reflect the microstructural transients, which are presented in an accompanying paper. It is shown that the data are reasonably consistent with a physically based internal state variable model for recrystallization. A feature of the modelling is the sensitivity analysis conducted, which indicates the degree of uncertainty in predicting recrystallization behaviour, and identifies the critical areas in which experimental effort should be concentrated.