ABSTRACTPrevious studies suggest that the implementation of universal precaution (UP) plays a role in reducing HIV stigma. In this study we investigate the efficacy of a stigma reduction intervention on UP compliance and explore whether UP compliance could potentially influence HIV stigma reduction in medical settings. A randomized controlled intervention trial was conducted in two provinces of China with 1760 healthcare service providers recruited from 40 county-level hospitals. Longitudinal analyses included data collection at baseline, 6-, and 12-month follow-up assessments. Using a hierarchical modeling approach, we estimated the intervention effect for each provider's UP compliance and its potential mediating role on HIV stigma with the bootstrapping method. A significant intervention effect on UP compliance was observed at both the 6- and 12-month follow-up assessments. The intervention effect on provider avoidance intent was partially mediated by the provider's own UP compliance at the two follow-up points. This study provides evidence that UP compliance should be part of HIV stigma reduction programs, especially in resource-restrained countries. Findings suggest that a protected work environment may be necessary but not sufficient to address HIV stigma in medical settings.