In recent years, magnesium alloys are attracting attention from aircraft and automotive industries because of their low density, high speci c strength and high damping capacity. However, magnesium alloys suffer from low ductility at room temperature. The improvement of ductility in AZ91D alloy through a new thermo-mechanical treatment (TMT) process was reported. This TMT process is based on simple uniaxial hot pressing in atmosphere. Uniaxial hot pressing was carried out at 673 K up to 67% compressive strain. After the hot pressing, the specimen was held isothermally at 673 K for various times. Hot pressed specimens were aged at 473 K. The specimen isothermally held for 3.6 ks showed tensile strength of 358 MPa and elongation to failure of 9.6%. Microstructural observation revealed that both high strength and ductility in AZ91D alloy were caused by the homogeneous distribution of ne intermetallic precipitates inside grains.