Objectives:Consenting donors for remnant clinical biospecimen donation is critical for scaling research biorepositories. Opt-in, low-cost, self-consenting for donations that solely relied on clinical staff and printed materials was recently shown to yield ∼30% consent rate. We hypothesized that adding an educational video to this process would improve consent rates.Methods:Randomized patients (by clinic day) in a Cardiology clinic received either printed materials (control) or the same materials plus an educational video on donations (intervention) while waiting to be seen. Engaged patients were surveyed at the clinic checkout for an “opt-in” or “opt-out” response. The decision was documented digitally in the electronic medical record. The primary outcome of this study was the consent rate.Results:Thirty-five clinic days were randomized to intervention (18) or control (17). Three hundred and fifty-five patients were engaged, 217 in the intervention and 158 in the control. No significant demographic differences were noted between treatment groups. Following an intention-to-treat analysis, the rate of opt-in for remnant biospecimen donation was 53% for the intervention and 41% for the control group (p-value = 0.03). This represents a 62% increase in the odds of consenting (OR = 1.62, 95% CI = 1.05–2.5).Conclusion:This is the first randomized trial showing that an educational video is superior to printed materials alone when patients are self-consenting for remnant biospecimen donation. This result adds to the evidence that efficient and effective consenting processes can be integrated into clinical workflows to advance universal consenting in medical research.