An historical analysis of privacy rights is the backdrop for a discussion of current constitutional interpretations of the fourth, fifth, and ninth amendments. The article considers whether drug testing violates the warrant clause and unreasonable search and seizure clauses of the fourth amendment, whether it abrogates the due process rights to liberty and property of the fifth and fourteenth amendments, and whether it impacts upon general constitutional privacy as developed in the ninth amendment and penumbras. This article concludes that President Reagan's proposed drug testing program for Federal employees does not meet these constitutional parameters for government action. Legally permissible conditions for the drug testing of public employees must include individualized suspicion as a prerequisite for testing, rigorous safeguards to ensure testing accuracy and reliability, and confidential test results. 298 footnotes.