BACKGROUND: Obese women undergoing cesarean section are at increased risk of postoperative infection. There is growing interest in negative pressure wound therapy (NPWT) to prevent closed surgical incision complications including surgical site infection; however, the evidence on the effectiveness and cost-effectiveness of this technology is limited. The objective of this study was to evaluate the cost-effectiveness of NPWT compared with that of standard dressing in preventing surgical site infection in obese women undergoing elective cesarean section based on current evidence and to estimate the value and optimal design of additiol research to study this technology. METHODS: The alysis was from the perspective of Queensland Health, Australia, using a decision model. Parameters were obtained from the published literature, a pilot clinical trial, and expert opinion. Monte Carlo simulation was performed to calculate the net monetary benefit, characterize decision uncertainty, and estimate the value of additiol research. Comparing the expected monetary benefits and costs of altertive trial sample sizes informed the optimal future study design. RESULTS: The incremental net monetary benefit of NPWT was Australian dollars 70, indicating that NPWT is cost-effective compared with that of standard dressing. The probability of NPWT being cost-effective was 65%. The estimated value of additiol research to resolve decision uncertainty would be Australian dollars 2.7 million. The optimal sample size of a future trial investigating the relative effectiveness of NPWT would be 200 patients per arm. CONCLUSIONS: Based on the current evidence, NPWT is cost-effective; however, there is high uncertainty surrounding the decision to adopt this technology. Additiol research is worthwhile before implementation.