A case of hemihypertrophy with many manifestations of a congenital neurocutaneous syndrome is presented; the previously reported cases of hemihypertrophy are reviewed and tabulated with many of their accompanying characteristics. The [See Table IV. in Source Pdf.] etiological hypotheses for hemihypertrophy that have been postulated in the literature are listed. The views expressed herein are those of the authors and do not necessarily reflect the views of the U.S. Navy nor the Department of Defense.