AIMS:People who inject drugs frequently experience discrimination. However, little is known about how discrimination experienced in different social domains is linked to health and wellbeing. DESIGN:We used data collected in 2016 from the Illicit Drug Reporting System (IDRS), an Australian survey of people who inject drugs. We used a modified version of the Discrimination Scale (DISC-12) to assess discriminatory behaviours in diverse social domains, including public institutions, neighbours, family and friends. We used the Kessler-10 scale, the Personal Wellbeing Index and specific items from the IDRS questionnaire to assess participants' health and wellbeing. FINDINGS:Sixty three percent of participants who responded to the discrimination module included in the IDRS 2016 (N = 796) reported ever having experienced discrimination due to their injecting drug use and 53% reported having experienced discrimination in the past month. Discrimination in all social domains analysed was linked with poor health and wellbeing, except for housing. Self-reported mental health problems and poorer general health were most frequently associated with discrimination. Participants who experienced discrimination from friends were three times more likely to report mental health problems (AOR=3.0, CI95=1.5-6.0). CONCLUSIONS:There are significant associations between the domains in which discrimination takes place and the health and wellbeing of people who inject drugs. Our findings highlighted the importance of assessing the social domains of discrimination in relation to mental health. Further research needs to assess not just whether a group or individual is discriminated against, but rather how they are likely to perceive this discrimination and how this experience can affect their life as a whole.