Lymphedema is one of the main late effects from breast cancer treatment affecting 3-60% of breast cancer survivors. Primarily occurring in the hand, arm, and/or affected breast, symptoms of lymphedema include swelling, pain, redness, restriction of arm/hand movement, tightness and feelings of fullness. These symptoms not only may limit physical functioning but also negatively affect quality of life, body image, social functioning, and financial status of breast cancer survivors with lymphedema. Unfortunately, there are no standardized methods for prevention, diagnosis, and treatment of breast cancer-related lymphedema. Despite its prevalence and lack of clinical guidelines, lymphedema is one of the most poorly understood, relatively underestimated, and least researched complications of cancer treatment. This chapter reviews the current problem of breast cancer-related lymphedema by investigating prevention and risk reduction strategies, diagnosis, and treatment. In addition, this chapter identifies future research opportunities focusing on prevention and risk reduction strategies, quality of life and physical function, surveillance, patient education, cost, diagnosis, and treatment. Challenges and recommendations for future research in these areas, particularly among underserved populations, are discussed.