Primary health care for drug users aims to promote health by providing a comprehensive harm-reduction package including outreach; peer-led interventions; information, education and communication; condoms; sterile injection equipment; and effective drug treatment including opioid substitution therapy. It also aims to reduce morbidity and mortality among all drug users by early identification and treatment of infections and other drug use-related illnesses; and provide care, treatment and support for HIV-infected drug users. These clinical guidelines are intended for use by doctors, nurses and other health-care workers who work in community outreach, drop-in centres, community clinics, drug treatment centres, prison clinics, and primary- and secondary-level hospitals. They offer guidance on the provision of primary health care to drug users and focus on the clinical management of common medical problems associated with drug use, in particular, injecting drug use in the presence or absence of HIV infection.