The creep response of a magnesium alloy friction stir welded joint has been investigated. The creep rates at 100 and 200 °C were lower in the cross-weld samples than in the base material. At 300 °C the creep rates of the welded samples overlap those obtained in the base material. This behavior, as a whole, was attributed to the overheating experienced by the weld metal, resulting in an increase in the amount of aluminum in solid solution and in grain growth.