This review demonstrates the role of the immune system in the development and progression of cardiac pathology caused by viral infection. The authors describe the role of lymphocytes (T- helper-17–Th17) in the viral persistence in myocardial tissue. They provide the information on increased level of interleukin-17A, the main Th17 cytokine in patients with dilated cardiomyopathy, which proves role of these cells in the progression of cardiac pathology. They discuss the role of T regulatory (Treg) lymphocytes in inflammatory heart disease.