Seven reasons for instituting urinalysis drug testing in law enforcement agencies are outlined: public safety, public trust, potential for corruption, presentation of credible testimony, morale in the workplace, loss of productivity, and civil liability. The article emphasizes that these rationales do not address whether drug testing will contribute substantially to the control of illegal drug use among officers. In this context, several issues are addressed: the validity of tests, interpreting positive results, and the efficacy of testing in detecting drug use. The article discusses two divergent lines of cases relating to the constitutionality of urinalysis drug testing: one permitting testing only on the basis of individualized, reasonable suspicion, and the other allowing testing in the absence of such suspicion. The future of random testing is explored. The authors conclude that the tremendous energy and resources necessary for effective random urinalysis programs could be better allocated to prevention programs. 29 footnotes.