Breast cancer represents one of the most common malignant diseases among women. In recent decades, a significant progress has been achieved in treatment of the disease and a considerable improvement in cancer specific survival rate has been registered. At the same time with the overall survival rate increase the risk of developing late treatment toxicity is growing. It has a negative impact on the quality of life and the overall mortality rate. This review describes the pathogenic aspects of radiation-related cardiac toxicity and organs at risk as well as sparing techniques in breast cancer radiotherapy.