The hot formability of a work-hardenable aluminium alloy AA5083 was studied by means of uniaxial compression testing at temperatures of 300–500°C and strain rates of 0.001–10 s⁻¹. The constants in the hyperbolic sine equation were compared with those in the literatures. Microstructure evolution during deformation and cooling was examined and the effects of temperature and strain rate on grain size were investigated. A high deformation temperature was found to favour static recrystallization, while a low strain rate facilitated dynamic recrystallization.