Abstract Objective To systematically review audio-visual (AV) interventions for promoting informed consent (IC) in clinical practice and to consider the impact of reading age adjustment. Methods Systematic review of randomized controlled trials (RCTs) comparing AV interventions to standard IC in clinical practice. Outcomes included recall (immediate <1 day; intermediate 1–14 days; late >14 days), satisfaction and anxiety. Data were synthesized using random effects meta-analyses. Comparisons were made between studies that did and did not adjust for participant reading age. Results Of 11,813 abstracts screened, 29 RCTs were eligible (30 intervention arms). Interventions included videos ( n = 17), computer programs ( n = 5), electronic presentations ( n = 3), compact discs ( n = 3) and websites ( n = 2). Meta-analysis showed AV interventions improved immediate recall (standardized mean difference SMD 0.64, 95% confidence interval CI 0.45–0.85). Results for intermediate and late recall were too heterogeneous to synthesize. AV interventions did not consistently affect either satisfaction or anxiety. Adjusting the reading age of interventions improved immediate recall (reading age interventions: adjusted SMD 1.21, 95%CI 0.81–1.61; non-reading age adjusted SMD 0.51, 95%CI 0.36–0.66). Conclusion AV interventions, especially those adjusted for participant reading age, improve immediate information recall for IC. Practice implications Wider use of AV aids is justified when obtaining IC in clinical practice.