After briefly reviewing the current dynamic status of corporate for-profit multihospital chains, the author traces their historical antecedents from early 20th century advances in medical care and medical education to the present economic and political environment that is so conducive to their growth. The chains' success in increasing their profitability in the general health care field through pricing and marketing strategies and efficient use of personnel has raised several concerns, but in combination with several other factors it has ensured the movement of for-profit corporations into the psychiatric field. The implications of this movement for the provision of psychiatric services are discussed, particularly the thrust to define psychiatry as a group of separately marketable products.