General agreement has been reached concerning the mechanics involved in the embryonal development of the various postanal cysts and sinuses usually grouped under the general term "pilonidal disease." The theory that these are due to epithelial sequestration has taken complete precedence over all previous suggestions linking the condition with preen glands or medullary outgrowths. There is no such unanimity, however, in regard to the proper surgical treatment, and the purpose of this paper is to summarize and review present opinion on this moot subject. It has often been said that wars offer an opportunity for mass experimentation in the management of disease, and this has been especially true during World War II in relation to pilonidal disease. Thousands of patients have been operated on by various technics with emphasis on closed surgical procedures. In the last few years a number of articles on the subject, almost entirely from military sources,