Medicinal opiates can produce both analgesia and euphoria. The mood altering action of this class of drugs has led to their abuse (non-medical use), a problem compounded by their physical dependence and addictive qualities. The legitimate expansion of clinical opioid analgesic use for severe chronic non-malignant pain, together with the introduction of high-dose extended-release (modified-release) oral tablet formulations of opioids with good bioavailability, has created increased opportunities for the illicit use of these prescribed drugs. Such use is now a major societal problem, with an incidence that appears to exceed the use of street narcotics such as heroin in the US. This review highlights the extent of the illicit use of prescribed opiate analgesics and some of the steps, legal, educational and pharmaceutical, that can be taken to potentially reduce the risk of their misuse or diversion for abuse.