Methadone is a synthetic opiate used in the treatment of opiate addiction. Various side-effects have been associated with the use of methadone. These include xerostomia, which can contribute to a high caries rate. The UK Regional Drug Misuse Database reported that around 118,500 drug users were receiving treatment from drug misuse agencies and GPs. The vast majority (87%) were receiving treatment from community specialist services. As many drug abusers have poor oral health, general dental practitioners are likely to encounter such individuals. It is essential therefore that dentists are aware of the potential difficulties that may be encountered when treating subjects receiving methadone. These problems may relate to previous drug abuse and to the effects of methadone therapy.