Radiation therapy is the main treatment for a large number of neoplastic diseases. Improved survival in this group of patients led to the emergence of a new nosological unit – radiation-induced damage to neighbouring organs and systems. Data accumulated in recent decades has proven conclusively that chest radiotherapy could result in heart damage. Cardiovascular diseases are the leading cause of death in oncological patients in remission. The onset of radiation-induced heart disease (RIHD) can be early with clinical picture of acute myocarditis and late with manifestations of constrictive pericarditis, restrictive cardiomyopathy, coronary artery disease, valvular involvement, heart failure and conduction pathology. Clinical symptoms may manifest years after exposure to radiation. Our team performed a mini-review on the topic, after which we shared our own experience in 10 patients who underwent radiation therapy in the past and were admitted to the Clinic of Cardiology of University Multyprofile Hospital for Active Treatment „Deva Mariya“ with a clinical picture of ACS.