Restrictive cardiomyopathy is a descriptive clinical and hemodynamic syndrome emphasizing the pathophysiologic mechanisms by which myocardial hypertrophy and/or infiltrative processes cause cardiocirculatory morbidity. This diagnosis can be made with precision only after pericardial construction is excluded and myocardial biopsy has identified the restrictive process. Though a variety of rather rare infiltrative pathological entities may be responsible for the restrictive cardiomyopathic picture, most commonly no definitive pathologic diagnosis is established despite extensive hemodynamic and histologic investigation. Nonetheless, a therapeutic trial with a calcium entry blocking agent is warranted.