Breast cancer is the leading type of cancer in women. Advances in the detection and treatment of breast cancer have increased the life expectancy and improved prognosis of the patients. Unfortunately, the quality of life of survived patients is severely disturbed due to the many side-effects caused by cancer treatments. Among the side effects, those of the cardiovascular system are the most worrisome. Cardiotoxicity has been implicated as the primary reason for excess morbidity and mortality in the former breast cancer patients. The most common side effects in the treatment of breast cancer are asymptomatic decrease in left ventricular ejection fraction and heart failure as a result of treatment containing anthracycline and trastuzumab. The cardiotoxicity of anthracyclines causes myocardial necrosis and injury and the consequences are often irreversible and permanent. On the other hand, the cardiotoxicity of trastuzumab causes a reversible myocardial contractility disorder. Tyrosine kinase inhibitors cause a decrease in left ventricular ejection fraction, arrhythmias and QT-prolongation. Cardiac side effects of CDK-4/6 inhibitors are QT-prolongation and venous thromboembolic events. Hormone therapy for breast cancer is associated with thromboembolic events and increased cardiovascular risk. Heart irradiation as a part of radiotherapy treatment of breast cancer can result in numerous cardiotoxic side-effects such as ischemic heart disease, cardiomyopathy, pericarditis and pericardial effusion, valve disease, and arrhythmias. Cardiac follow-up of patients treated for breast cancer includes a thorough personal and family history, clinical examination, imaging and laboratory tests. With an interdisciplinary cardio-oncological approach in the treatment of breast cancer, it is possible to detect and treat cardiac side effects early, but also to continue oncological treatment of breast cancer, which achieves better treatment outcomes and quality of life.