Cardiovascular diseases are the leading global cause of death. Cardiomyopathies are the most prevalent forms of heart failure diseases currently. They may have genetic or environmental etiology, and the development of an autoimmune process is essential for the progression of the disease. During an autoimmune response, there is the breakdown of self-tolerance and generation of a T-lymphocytes-mediated cellular autoimmune response and B-lymphocytes-mediated humoral autoimmune response. Lymphocytes perpetuate the autoimmune response throughout the release of cytokines, expansion of autoreactive clones, and attenuation of regulatory mechanisms. Increasing evidences indicate that interferon (IFN)-γ and interleukin (IL)-17 participate during autoimmune disorders development. The use of autoimmune cardiomyopathy models revealed antagonistic functions for both cytokines during the evolution of autoimmune cardiomyopathy: while enhanced IFN-γ levels are associated to a lower disease severity, the levels of IL-17 are inversely correlated to a favorable prognosis. More precisely, recent findings indicate that the IFN-γ/IL-17 ratio in combination with other cytokine levels dictates heart’s autoimmunity development and dilatation. In this chapter, we discuss the role played by the autoimmune response in the development of cardiomyopathy. We also discuss some immune mechanisms focused on IFN-γ and IL-17’s ability to induce and perpetuate cardiac autoimmunity.