Giant cell myocarditis (GCM) is a rare and frequently fatal disorder with no proven treatment. It is a disease of young, predominantly healthy adults. Without transplantation, patients usually die of heart failure and ventricular arrhythmias. Due to the poor prognosis of the condition, prompt recognition and diagnosis are of clinical importance. Approximately 19% of these cases are associated with autoimmune diseases. The present article describes two unique cases of GCM associated with autoimmune diseases not previously reported in the literature - discoid lupus erythematosis and autoimmune hepatitis. A review of the natural history and treatment of GCM is also presented.