A method of temporarily reducing the diameter of a stent graft (10) and a stent graft with its diameter reduced. The stent graft has a tubular body and self expanding stents. The method comprising extending a release wire (18, 20) part helically along the graft material tube from substantially one side of the graft material tube at one end (14) of the graft material tube to substantially the opposite side of the graft material tube at the other end (12) of the graft material tube along the stent graft and stitching the release wire into the graft material tube, at each of a number of positions along the release wire looping flexible threads (22, 24) around the release wire and extending the flexible threads laterally around the circumference of the stent graft in each direction to a position away from the release wire, engaging the first flexible threads into the graft material or around struts of the stent, and drawing the ends of the thread together and tying ends of the thread to thereby temporarily reduce the overall diameter of the stent graft.