BACKGROUND: Despite the widespread implementation of electronic health records (EHRs), there is growing evidence that racial/ethnic minority patients do not use portals as frequently as non-Hispanic whites to access their EHR information online. This differential portal use could be problematic for health care disparities since early evidence links portal use to better outcomes. OBJECTIVE: We sought to understand specific barriers to portal use among African American and Latino patients at Kaiser Permanente, which has had a portal in place for over a decade, and broad uptake among the patient population at large. METHODS: We conducted 10 focus groups with 87 participants in 2012 and 2013 among African American and Latino Kaiser Permanente members in the mid-Atlantic, Georgia, and Southern California regions. Members were eligible to participate if they were not registered for portal access. Focus groups were conducted within each racial/ethnic group, and each included individuals who were older, had a chronic disease, or were parents (as these are the three biggest users of the portal at Kaiser Permanente overall). We videotaped each focus group and transcribed the discussion for analysis. We used general inductive coding to develop themes for major barriers to portal use, overall and separately by racial/ethnic group. RESULTS: We found that lack of support was a key barrier to initiating portal use in our sample-both in terms of technical assistance as well as the fear of the portal eroding existing personal relationships with health care providers. This held true across a range of focus groups representing a mix of age, income, health conditions, and geographic regions. CONCLUSIONS: Our study was among the first qualitative explorations of barriers to portal use among racial/ethnic subgroups. Our findings suggest that uniform adoption of portal use across diverse patient groups requires more usable and personalized websites, which may be particularly important for reducing health care disparities. This work is particularly important as all health care systems continue to offer and promote more health care features online via portals.