Myocarditis can present for evaluation with a wide range of signs and symptoms. The initial evaluation of these patients requires a high index of suspicion and often involves the performance of various diagnostic and laboratory tests. There are many infectious causes of myocarditis, the most common of which include several viruses, but there are still situations where a causative agent is never identified. The treatment of myocarditis is supportive, including mechanical ventilation and inotropic medications in some patients. The use of immune modulators such as immune globulin or glucocorticoids remains controversial, but both are commonly used clinically. The outcomes of patients with myocarditis span the entire spectrum from complete recovery to the development of dilated cardiomyopathy, the need for heart transplantation, and death.