Renovascular hypertension (RVH) is an important cause of hypertension in children. It is essential to assess the hemodynamics of RVH lesions in detail. We herein report the case of a 9-year-old female with RVH caused by left renal artery stenosis in which the hemodynamics of the lesions were assessed with time-resolved three-dimensional cine phase-contrast MRI (3D cine PC MRI) with a vastly undersampled 3D radial projection imaging trajectory before and after percutaneous transluminal renal angioplasty (PTRA). The utility of 3D cine PC MRA for diagnosing RVH and evaluating the renal blood flow pre- and post-PTRA is presented. J. Magn. Reson. Imaging 2015;41:165–168. © 2014 Wiley Periodicals, Inc.