One source of drug abuse is the diversion of a controlled substance used for medical purposes toward purposes of abuse or sale. Prescription drugs account for between 25 to 30 percent of all drug abuse episodes. Preventing the diversion of prescribed drugs is a responsibility to be shared by prescribers, law enforcement officials, pharmacists, manufacturers, and regulatory bodies. For controlled substance prescriptions to be lawful, the prescription must be issued for a legitimate medical purpose by a practitioner acting in the usual course of his or her practice, with medical records indicating the conditions leading up to the prescription of the drug. This article discusses the various ways in which prescriptions may be written by members of the medical profession, unlawfully, in the absence of a thorough medical exam, and in order to help out friends or family members; and discusses the importance of using law enforcement officials to aid in the prevention of prescription medicine abuse. One primary way in which law enforcement officials may aid pharmacists and physicians in drug abuse prevention is to keep medical practitioners informed of behaviors that are often demonstrated by drug seekers. This article discusses the various legal issues imposed on prescription drugs by the Federal Comprehensive Drug Abuse Prevention and Control Act of 1970. This Act details under what conditions prescriptions may be issued and for which drugs. Following a discussion of the role of the pharmacy in prevention diversion through scrutinizing prescriptions is also presented. The diversion of prescription medications create a multitude of problems which may be addressed through educational and investigative efforts from various agencies, including law enforcement officials.