At present the number of cancer survivors is still increasing. However, their long-term quality of life after anticancer treatment can be decreased. Radiotherapy may represent a risk for the future of some oncologic patients. The late cardiovascular effects of radiotherapy to the area of thorax, cranium and to the abdominal area are the actual multidisciplinary problem. The unique problem is mediastinal radiotherapy which may induce the development of the cardiomyopathy, constrictive pericarditis, coronary artery disease, myocardial infarction, valvular defects, arrhythmias and other complications. Exact knowledge of pathophysiological mechanisms of radiation induced cardiovascular damage after radiotherapy as well as using of new diagnostic cardiologic methods might be useful for the detection of subclinical abnormalities and their early treatment already in the asymptomatic patients.