Substance abuse is a signiﬁcant risk factor for the acquisition of HIV infection by direct means, such as sharing of injecting equipment, and indirect means such as risk behaviour associated with impaired judgment while intoxicated. Substance abuse is especially prevalent in people with HIV infection with reported rates ranging from 50-75%. It is important to note that there is a common comorbidity between substance abuse disorders and other psychiatric diagnoses and patients will beneﬁt from a coordinated assessment approach. The general approach is to: take a comprehensive history of substance use in an empathic and accepting manner; provide education about harm reduction strategies associated with drug use; and make an assessment of a person’s commitment to changing behaviour. A commitment to changing behaviour has been classiﬁed according to a Stages of Change Model  that includes stages of pre-contemplation, contemplation, preparation, action and maintenance. There are speciﬁc psychological therapies that have been shown to be effective in helping people make and maintain changes in behaviour. Psychosocial interventions aimed at stabilising a person’s living circumstances can assist and have beneﬁcial effects on maintaining health. There are pharmacological strategies that have been shown to be beneﬁcial, particularly when combined with psychological interventions. Initiating some of these pharmacological therapies may require specialist assessment. A person considering abruptly ceasing use, especially of alcohol, should consider a speciﬁc detoxiﬁcation program to prevent the potential complications of withdrawal.