As the term implies, congenital lymphedema is a condition characterized by edema which is the result of an increased quantity of lymph in the tissues at birth. The terms lymphedema and elephantiasis are not synonymous. According to Middleton,1 the term elephantiasis "apparently originated as a soldiers' slang expression in the Roman army during the Libyan campaign." It probably indicated swelling of the legs to elephantine proportions. The word does not indicate the nature of the swelling. The term "swollen legs" does not constitute a diagnosis, and elephantiasis is likewise entirely inadequate. In the medical literature the term elephantiasis is used to indicate arteriovenous fistula and other anomalies of blood vessels, fibrous hypertrophy, neuromatosis and lymphangioma, in addition to lymphedema. The use of the term has led to confusion, and since continuation of it in the medical literature increases this undesirable situation, we believe that clarity is best served by entire discontinuation of the term elephantiasis.Two types of congenital lymphedema exist: simple and familial. Simple congenital lymphedema affects individual persons in a family ; familial congenital lymphedema affects a sufficient number of blood relatives to indicate that a disturbance in the genes is responsible. This condition, which is known as Milroy's disease, after the original descrip¬ tion by Milroy,2 is a definite clinical syndrome which we have never observed. We doubt that this syndrome has been observed by many other authors who have described cases with the designation "Milroy's disease." As one of us (E. V. A.3) has pointed out, various authors have departed greatly from the criteria of Milroy ; the term should be reserved for lymphedema which is both congenital and familial.