Lanthanum acted as a grain refiner for Mg-3Al alloys reducing the grain size upto ∼5.8 μm. Lanthanum (2.5%) can enhance the ductility of Mg-3Al alloy to 22%. Lanthanum can serve as strengthening element in Mg-3Al alloy under both tensile and compressive loadings. Addition of La assists in improving the damping performance of Mg-3Al alloy.