Friction stir welding (FSW) is a key process considered for critical structures as railways rolling stock, aircraft fuselage panels and shipbuilding, and other applications. There is widespread interest in the use of FSW aluminium alloys, aiming at moving from fastened structures with many components, to integral monolithic structures with economies in part number, fabrication time, weight and cost. The damage tolerance of the resulting structures is not as well understood as in the case of earlier manufacturing techniques, and there is a need for data concerning the fatigue behaviour of FSW joints in a variety of situations. The present contribution presents a comparison of fatigue data for joints manufactured using FSW.