BACKGROUND: Consumers rarely use publicly reported health care quality data. Despite known barriers to use, few studies have explored the effectiveness of strategies to overcome barriers in vulnerable populations. METHODS: This randomized controlled trial tested the impact of a patient navigator intervention to increase consumer use of publicly reported quality data. Patients attending an urban prenatal clinic serving a vulnerable population enrolled between May 2013 and January 2015. The intervention consisted of 2 in-person sessions in which women learned about quality performance and viewed scores for local practices on the Massachusetts Health Quality Partners Web site. Women in both the intervention and control arms received a pamphlet about health care quality. Primary study outcomes were mean clinical quality and patient experience scores of the practices women selected (range 1-4 stars). RESULTS: Nearly all (726/746; 97.3%) women completed the study, 59.7% were Hispanic, and 65.1% had a high school education or less. In both unadjusted and adjusted models, women in the intervention group chose practices with modestly higher mean clinical quality (3.2 vs 3.0 stars; P = .001) and patient experience (3.0 vs 2.9 stars; P = .05) scores. When asked to rate what factors mattered the most in their decision, few cited quality scores. CONCLUSIONS: An intervention to reduce barriers to using publicly reported health care quality data had a modest effect on patient choice. These findings suggest that factors other than performance on common publicly reported quality metrics have a stronger influence on which pediatric practices women choose.