Growing experimental and clinical data highlights the important roles of increased reactive oxygen species production in cardiovascular remodeling (CR). Oligomeric grape seed proanthocyanidins (GSPs) have been shown to be potent antioxidants and free radical scavengers. Mice were treated with DOCA-salt to induce CR and were given distilled water or oligomeric GSPs for 4 weeks. The heart weight (HW) index and kidney weight (KW) index were expressed as heart weight/body weight (HW/BW) and kidney weight/body weight (KW/BW); the histological changes were investigated by hematoxylin and eosin and Van Gieson staining.The endothelial-dependent vasodilation function induced by acetylcholine was investigated in isolated thoracic aorta ring. Colorimetric analysis was used to assay superoxide dismutase (SOD) activity, malondialdehyde (MDA) content and nitric oxide (NO) content in serum and hydroxyproline content in cardiac tissue. Administration of GSPs markedly alleviated the elevation of HW/BW ratio, KW/BW ratio and cross-sectional area of cardiomyocytes, decreased collagen deposition in heart and attenuated histopathology injury, and improves endothelial-dependent aorta ring relaxation in vitro accompany by increasing of NO content in serum. Meanwhile, treatment with GSPs significantly ameliorated oxidative stress via increasing SOD activities and decreasing MDA formation. These findings suggest that administration of GSPs has the potential to attenuate DOCA-salt induced CR and KH and preserve NO activity and endothelial function, which mechanism may contribute to its antioxidant characteristic, at least in part. Copyright © 2012 John Wiley & Sons, Ltd.