Orchiopexy is a common surgical procedure for the treatment of cryptorchidism in the pediatric population, with a high incidence of postoperative nausea and vomiting (PONV). Recent evidence suggests that systemic inflammation may contribute to PONV pathogenesis, and preoperative inflammatory biomarkers such as NLR, PLR, SII, MLR, and SIRI could serve as predictive indicators. This prospective observational study aims to evaluate the relationship between these biomarkers and PONV incidence in children undergoing orchiopexy.