Comprehensive flow velocity acquisition based on time-resolved three-dimensional phase-contrast CMR with three-directional velocity encoding was employed to assess arterial hemodynamics in a patient with a large patent ductus arteriosus with Eisenmenger's physiology. Computer-aided visualization of blood flow characteristics provided detailed information about temporal and spatial distribution of left and right ventricular outflow. Main findings included the depiction of the location and extent of two flow channels for systolic aortic filling, a relatively large amount of pulmonary artery to aortic flow confirming Eisenmenger's physiology, and a slight phase difference between right and left ventricular ejection. These results illustrate the feasibility of flow sensitive 3D CMR at 3T in relation to a potential field of clinical application such as congenital heart disease with abnormal vascular connections or shunt flow.