The presence of lymphatic vessels has been known for centuries, but the key players regulating the lymphatic vessel growth and function have only been discovered during the recent decade. The lymphatic vasculature is essential for maintenance of normal fluid balance and for the immune response. Hypoplasia or dysfunction of the lymphatic vessels can lead to lymphedema. Currently, lymphedema is treated primarily by physiotherapy, compression garments, and occasionally by surgery, but the means to reconstitute the collecting lymphatic vessels and cure the condition are limited. Specific growth factor therapy has been used in experimental models to regenerate lymphatic capillaries and collecting vessels after surgical damage. Recent results provide a new concept of combining growth factor therapy with lymph node transplantation as a rationale for treating secondary lymphedema. Lymphatic vessels are also involved in lymph node and systemic metastasis of cancer cells; our understanding of mechanisms of lymphatic metastasis has increased remarkably.