Abstract Background First-case tardiness is still a common source of frustration. In this study, a nationwide operating room (OR) Benchmark database was used to assess the effectiveness of interventions implemented to reduce tardiness and calculate its economic impact. Methods Data from 8 University Medical Centers over 7 years were included: 190,295 elective inpatient first cases. Data were analyzed with SPSS statistics and multidisciplinary focus-group study meetings. Analysis of variance with contrast analysis measured the influence of interventions. Results Seven thousand ninety-four hours were lost annually to first-case tardiness, which has a considerable economic impact. Four University Medical Centers implemented interventions and effectuated a significant reduction in tardiness, eg providing feedbacks directly when ORs started too late, new agreements between OR and intensive care unit departments concerning “intensive care unit bed release” policy, and a shift in responsibilities regarding transport of patients to the OR. Conclusions Nationwide benchmarking can be applied to identify and measure the effectiveness of interventions to reduce first-case tardiness in a university hospital OR environment. The implemented interventions in 4 centers were successful in significantly reducing first-case tardiness.