In this study, the influence of sheet thickness, loading rate, and punch diameter on the bending behaviour of twin-roll cast, rolled and heat-treated AZ31 magnesium alloy was investigated. Therefore, the 3-point bending test was performed at room temperature using an electromechanical testing machine (v = 0.1−10 mm/s) with different punch diameters (D = 2 mm, 8 mm, 16 mm). The initial material has a recrystallized microstructure with grain sizes of 6−9 µm. It is shown by the mechanical investigations that the bending force increases with the sheet thickness. In contrast to this, the bending angle is independent of the sheet thickness. In addition, the punch diameter and the loading rate do not influence the maximum force and the bending angle significantly.