Postoperative nausea and vomiting (PONV) is one of the most common and unpleasant postoperative complications in children. This study aims to evaluate the efficacy and safety of using dexamethasone alone or combined other drugs on the incidence of PONV in children. A systematic search of the literature was conducted from inception until March, 2019. Literature selection and data extraction were conducted by two independent reviewers. Statistical analysis was performed using the software package Review Manager Version 5.3.3. Twenty studies with total 2505 participants were included. The pooled analysis used a random-effect model showed that dexamethasone had significantly greater efficacy in incidence of POV and PON in postoperative 24 h than control. Subgroup analysis indicated the RR of dexamethasone >= 0.5 mg/kg group was the lowest compared subgroup dexamethasone <= 0.3 mg/kg and 0.3-0.5 mg/kg. There was no difference for early POV between dexamethasone and placebo groups. Dexamethasone combined with others also could significantly reduce the incidence of POV in postoperative 24 h. Few adverse effects were reported. This study indicates that dexamethasone is effective for preventing incidence of PONV in children. And multimodal approaches have shown more effectively to prevent the incidence of POV. (C) 2020 Asian Surgical Association and Taiwan Robotic Surgery Association. Publishing services by Elsevier B.V.