Abstract Lymphedema is a common and morbid complication of cancer treatment. To date, lymphedema treatment has been palliative aiming to prevent disease progression and improve symptoms of swelling. Development of novel therapies for lymphedema has been limited by the fact that the pathophysiology of the disease remains unknown. While it is true that lymphatic injury during surgery is an important initiating event, the mechanisms that regulate the development of the disease in a subset of patients remain unknown. Recent studies in our lab have suggested that the pathophysiology of lymphedema is related to inflammatory changes that occur following surgery. We have shown that CD4+ T cells play a key role in the pathology of lymphedema by orchestrating a variety of changes including tissue fibrosis, lymphatic leakiness, impaired collecting vessel pumping, and changes in the lymphatic smooth muscle cells. More importantly, in preclinical models we have shown that inhibition of this response can prevent development of lymphedema following surgery or reverse it once it has been initiated. These findings have led to novel treatments for lymphedema that may be effective either as standalone therapies or used in conjunction with surgical treatments for lymphedema. Citation Format: Mehrara B. Lymphedema management in 2018: Are we making any progress? [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr ES11-1.