--- - |2+ Abstract Aim Dilated cardiomyopathy (DCM) is is characterised by left ventricular dilation and associated with systolic dysfunction. Recent evidence has reported the high expression of latent transforming growth factor beta‐binding protein 2 (LTBP2) in heart diseases, which may play a role in regulating multiple biological functions of myocardial cells. Thus, this study set out to investigate the molecular mechanism and effects of LTBP2 in myocardial oxidative stress injury, fibrosis and remodeling in a rat model of DCM, with the involvement of NF‐κB signaling pathway. Methods The rat model of DCM was treated with si‐LTBP2 and/or activator of NF‐κB signaling pathway to examine the hemodynamic indexes, cardiac functions, oxidative stress injury, fibrosis and remodeling. Moreover, in vitro experiments were conducted to verify the regulatory role of LTBP2 and NF‐κB signaling pathway in DCM. Results LTBP2 was upregulated in DCM rats. After LTBP2 was knocked down, hemodynamic indexes, HW/BW ratio, collagen volume fraction (CVF) level, positive expression of LTBP2, levels of reactive oxygen species (ROS), malondialdehyde (MDA), interleukin‐6 (IL‐6), tumor necrosis factor‐alpha (TNF‐α), tumor necrosis factor‐beta 1 (TGF‐β1) and brain natriuretic peptide (BNP) were all decreased. Meanwhile, levels of LTBP2, Col‐I, Col‐III, p65 and p52 were also reduced, while HW, BW and levels of SOD and TAOC were increased. In contrast, activation of NF‐κB signaling pathway reversed effects of LTBP2 gene silencing. These findings were confirmed by in vivo experiments. Conclusions LTBP2 silencing can attenuate myocardial oxidative stress injury, myocardial fibrosis and myocardial remodeling in DCM rats by down‐regulating NF‐κB signaling pathway. - 'Acta Physiologica, Volume 0, Issue ja, -Not available-. '