Objective: Systematic reviews (SRs) are the cornerstone of evidence-based medicine. In this study, we evaluated the effectiveness of using two computer screens on the efficiency of conducting SRs. Study Design and Setting: A cohort of reviewers before and after using dual monitors were compared with a control group that did not use dual monitors. The outcomes were time spent for abstract screening, full-text screening and data extraction, and inter-rater agreement. We adopted multivariate difference-in-differences linear regression models. Results: A total of 60 SRs conducted by 54 reviewers were included in this analysis. We found a significant reduction of 23.81 minutes per article in data extraction in the intervention group relative to the control group (95% confidence interval: -46.03, -1.58, P = 0.04), which was a 36.85% reduction in time. There was no significant difference in time spent on abstract screening, full-text screening, or inter-rater agreement between the two groups. Conclusion: Using dual monitors when conducting SRs is associated with significant reduction of time spent on data extraction. No significant difference was observed on time spent on abstract screening or full-text screening. Using dual monitors is one strategy that may improve the efficiency of conducting SRs.