Chronic intermittent hypoxia (CIH), the hallmark of obstructive sleep apnea syndrome (OSAS), has been reported to play a key role in the development of OSAS-associated cardiovascular diseases including cardiac remodeling. RhoA/Rhokinase (ROCK) pathway has also been implicated in myocardial remodeling, but the exact mechanisms are not fully elucidated. This study's purpose is to investigate the influence of fasudil, a selective ROCK inhibitor, on CIH-induced left ventricular remodeling in rats and its possible mechanisms. Adult male Sprague-Dawley rats suffered from CIH or normoxia stimulus and were intervened with vehicle or fasudil (10 mg.kg(-1).d(-1), intraperitoneal injection) for 6 weeks. In this study, treatment with fasudil significantly reversed intermittent hypoxia-induced histopathological transformations and ultrastructural changes in rat myocardium. Moreover, fasudil downregulated the protein levels of RhoA and phosphorylation of myosin phosphatase targeting subunit-1 (MYPT1), thus effectively inhibited the activation of RhoA/ROCK signaling pathway. Simultaneously, activity of nuclear factor (NF)-kB was suppressed by fasudil, which was accompanied by reduced NF-kB downstream inflammatory genes including interleukin-6, tumor necrosis factor-a and monocyte chemotactic protein-1, and apoptosis. These results suggest that fasudil attenuates myocardial remodeling in CIH rats, at least partly by suppressing activation of NF-kB. Inhibition of the RhoA/ROCK pathway could become an important therapeutic target in the prevention of OSAS-related cardiomyopathy.