Abstract Background and objectives: Contribution margin per hour (CMH) has been proposed in healthcare systems to increase the profitability of operating suites. The aim of our study is to propose a simple and reproducible model to calculate CMH and to increase cost-effectiveness. Methods: For the ten most commonly performed surgical procedures at our Institution, we prospectively collected their diagnosis-related group (DRG) reimbursement, variable costs and mean procedural time. We quantified the portion of total staffed operating room time to be reallocated with a minimal risk of overrun. Moreover, we calculated the total CMH with a random reallocation on a first come-first served basis. Finally, prioritizing procedures with higher CMH, we ran a simulation by calculating the total CMH. Results: Over a two-months period, we identified 14.5 hours of unutilized operating room to reallocate. In the case of a random ‘‘first come -first serve’’ basis, the total earnings were 87,117 United States dollars (USD). Conversely, with a reallocation which prioritized procedures with a high CMH, it was possible to earn 140,444 USD (p < 0.001). Conclusion: Surgical activity may be one of the most profitable activities for hospitals, but a cost-effective management requires a comprehension of its cost profile. Reallocation of unused operating room time according to CMH may represent a simple, reproducible and reliable tool for elective cases on a waiting list. In our experience, it helped improving the operating suite cost-effectiveness.