Magnetic resonance is becoming an increasingly used examination in cardiology, since it greatly improves the accuracy of diagnosing of many heart diseases. At present magnetic resonance is the gold standard in assessing the volumes of the heart chambers and the systolic function of both ventricles. The possibility of detecting tissue characteristics to refine the diagnostics of different types of myocardial pathology is of essential importance. The authors summarize in the article the present knowledge about the use of magnetic resonance of the heart in the field of myocardial disease, i.e. cardiomyopathy and myocarditis. In the first of this article, a general overview of cardiac magnetic resonance examination has been given, followed by detailed description of its usefulness in dilated cardiomyopathy and myocarditis, in hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy. The second part of the review summarizes the benefits of cardiac magnetic resonance examination in cardiac amyloidosis and other less common cardiomyopathies.Key words: fibrosis - cardiomyopathy - magnetic resonance - myocarditis - late contrast agent saturation.