BACKGROUND: Interpersonal trust plays an important role in the clinic visit. Clinician trust in the patient may be especially important when prescribing opioid analgesics because of concerns about misuse. Previous studies have found that non-white patients are perceived negatively by clinicians. OBJECTIVE: To examine whether clinicians' trust in patients differed by patients' race/ethnicity in a socially marginalized cohort. DESIGN: Cross-sectional study of patient-clinician dyads. PARTICIPANTS: 169 HIV infected indigent patients recruited from the community and their 61 primary care providers (PCPs.) MAIN MEASURES: The Physician Trust in Patients Scale (PTPS), a validated scale that measures PCPs' trust in patients. KEY RESULTS: The mean PTPS score was 43.2 (SD 10.8) out of a possible 60. Reported current illicit drug use and prescription opioid misuse were similar across patients' race or ethnicity. However, both patient illicit drug use and patient non-white race/ethnicity were associated with lower PTPS scores. In a multivariate model, non-white race/ethnicity was independently associated with PTPS scores 6.3 points lower than whites (95% CI: -9.9, -2.7). Current illicit drug use was associated with PTSP scores 5.5 lower than no drug use (95% CI -8.5, -2.5). CONCLUSION: In a socially marginalized cohort, non-white patients were trusted less than white patients by their PCPs, despite similar rates of illicit drug use and opioid analgesic misuse. The effect was independent of illicit drug use. This finding may reflect unconscious stereotypes by PCPs and may underlie disparities in chronic pain management. © 2011 The Author(s).