ALTHOUGH MUCH attention and time have been given to the nomenclature, etiology, diagnosis, and management of this condition, "eventration of the diaphragm" remains a controversial subject. Jean Louis Petit is credited with the description of this condition at postmortem examination in 1774. Although in itself a gross misnomer, the term eventration of the diaphragm coined by Beclard more than 135 years ago is better recognized and clinically more descriptive than numerous other definitions, including "idiopathic high lying diaphragm," "relaxatio diaphragmatica," "relaxed diaphragm," "insufficiency of diaphragm," "high level or elevated diaphragm," etc, and "neurogenic muscular aplasia" added in 1960.1 While relatively a rare condition, its occurrence warrants full knowledge of diagnosis and management. Chin and Lynn2 found 32 cases in 412,000 subjects in a mass x-ray survey, an incidence of approximately one to 1,400. It is encountered twice more often in the man than in woman and seen nine