Even today, myocarditis remains a disease that often occurs in young and middle-aged people, but unfortunately its diagnosis is difficult to confirm. Diagnosis of viral myocarditis is a challenge as the diagnostic tools used until recently lacked high sensitivity and specialty. Proper history, detailed clinical examination, hematological and serological examinations, electrocardiogram and imaging tests including echocardiogram and cardiac magnetic resonance have so far helped to diagnose patients with potential myocarditis. Nevertheless, the introduction of new immunohistological and molecular techniques in the diagnostic approach of patients with possible myocarditis helps significantly not only in the precise diagnosis but also in the setting of a treatment plan based on the exact etiology of myocarditis. However, endomyocardial biopsy and the application of the above techniques require a high degree of specialization and experience. Important questions remain, in particular, about which patients and to what extent will be benefit from immunosuppressive therapy. Also, more research is needed in the field of targeted treatment of viral myocarditis. It is clear that in order to achieve effective treatment of myocarditis, medical science needs to fully analyze and understand the pathophysiological pathways activated in the course of a myocarditis.