Following a review of management and player perspectives on such programs and a discussion of complications relating to the celebrity status of many of the testees, a variety of such programs are described. These include those implemented in horse and harness racing, baseball, boxing, football, the National Hockey League, and amateur/college sports. These programs are described in terms of authorization to test, substance lists, sanctions, selection methods, confidentiality provisions, and exceptions. Challenges against five such programs then are reviewed including those based on fourth amendment search and seizure provisions, the California Constitution, the fourth amendment and the Washington State Constitution combined, equal right protections, due process right to a hearing, the privacy interest in confidentiality, defamation, and contractual claims. Future sources of challenges, particularly those arising from State constitutions, also are considered. Of five programs challenged thus far, only the New Jersey Horse Racing Program has fully withstood the challenge made against it. It is suggested that in professional sports, where fan appeal, as well as safety interests, has been used to justify involuntary, noncause testing, testing issues should be resolved through collective bargaining. In amateur sports, testing should be voluntary or based on cause. 461 footnotes.