Four-dimensional (4D) flow was measured in 20 patients with dilated ascending aorta (AA) and in 20 controls. Aortic flow was displaced from the center line of the AA in patients with AA dilatation. Flow displacement was present in the proximal and tubular parts of AA. Total wall shear stress (WSS) was higher on the displaced side compared to the opposite side of the aorta. The circumferential WSS (WSSC) ratio to total WSS was higher in the inner curvature of dilated AA in the proximal part and WSSc was elevated in the whole aortic ring in the distal part of AA.