Despite substantial evidence that nitric oxide (NO) and/or endogenous S -nitrosothiols (SNOs) exert protective effects in a variety of cardiovascular diseases, the molecular details are largely unknown. Here we show that following left coronary artery ligation, mice with a targeted deletion of the S -nitrosoglutathione reductase gene (GSNOR −/− ) have reduced myocardial infarct size, preserved ventricular systolic and diastolic function, and maintained tissue oxygenation. These profound physiological effects are associated with increases in myocardial capillary density and S -nitrosylation of the transcription factor hypoxia inducible factor-1α (HIF-1α) under normoxic conditions. We further show that S -nitrosylated HIF-1α binds to the vascular endothelial growth factor (VEGF) gene, thus identifying a role for GSNO in angiogenesis and myocardial protection. These results suggest innovative approaches to modulate angiogenesis and preserve cardiac function.