Progress in cancer treatment induced a greater use of specific therapies for an increasing number of patients. These treatments can cause long lasting sequelae, which may reduce the quality of life of the concerned people. Lymphedema of the arm after primary treatment for breast cancer is generally a chronic morbidity, which can have serious consequences for patients including restriction of social and business activities. The present article gives an overview of causes, possible prevention and treatment of this condition, which affects in variable magnitude 25% of the women after breast cancer treatment. Primary prevention (less invasive surgery and less extensive radiotherapy) is extremely important, as an established lymphedema is not curable. However secondary and tertiary prevention, early detection and treatment, play the decisive role in the every day life.