This manuscript reviews the role of nitrite and NO dependent mechanisms in the regulation of cardiovascular system. The endo- and exogenous sources of nitrite as well as different pathways of its formation discussed in respect to nitrite reductases activities and nitric oxide formation. The role of nitrite and its metabolites in the regulation of myocardium contractility and effect on peripheral blood resistance are reviewed as well as its dependence from redox and cyclooxygenase reaction. Multiple data supporting the role of nitrite and NO in energy homeostasis and mitochondrial respiration are provided. Additionally, some molecular aspects of cardioprotective, pathological and eco-physiological effects of nitrite are discussed.