This article updates a similar article published in 1987, pointing out that it is now clear that public sector drug testing by urinalysis is a search to which the fourth amendment applies. Courts have rejected the claim, however, that the fifth amendment prohibition against self-incrimination applies to evidence obtained by urinalysis. Unreliable urinalysis results that cause an employee to be fired could trigger a substantive due process claim under the fourteenth amendment. While Federal courts are sympathetic with employers who wish to test their employees for illicit drug use, they are aware of employees' claims to constitutional protections. Mandatory tests must be justified by the nature of the work involved and must be conducted under a policy that minimizes intrusions on employee privacy. 68 footnotes.