Radiographic delineation of peripheral lymphatic vessels and of lymph nodes has aided in the specific diagnosis of regional edema and lymphatic neoplasms. Whereas anatomic abnormalities in lymphatic vessels are an infrequent finding in all types of primary venous disease, patients with primary lymphedema have shown dilatation, tortuosity, fragmentation, and obstruction of lymph vessels. Primary and secondary lymphatic neoplasms show abnormal radiologic patterns in involved nodes. Postsurgical edema may be predictable on the basis of preoperative lymphatic visualization. In patients who are found before operation to have limited lymphatic drainage, modification of the contemplated surgery, intensive prophylactic care of the extremity against edema after operation, or eventual surgical reconstruction of lymphatic drainage may be considered.