The aim of this study was to specifically determine the impact of a fixed dose of ginger administration, compared with placebo, on the 24-hour postoperative nausea and vomiting. The design was a systematic review and metaanalysis of trials revealed by searches. Randomized controlled trials comparing ginger with placebo to prevent postoperative nausea and vomiting and postoperative vomiting from Medline, IPA, CINAHL, Cochrane CENTRAL, HealthStar, Current Contents, bibliographies of retrieved articles, contact of authors, and experts in the field. Two reviewers selected studies for inclusion and independently extracted data. Five randomized trials including a total of 363 patients were pooled for analysis of preventing postoperative nausea and vomiting and postoperative vomiting. The summary relative risks of ginger for postoperative nausea and vomiting and postoperative vomiting were 0.69 (95% confidence interval 0.54 to 0.89) and 0.61 (95% confidence interval 0.45 to 0.84), respectively. Only one side effect, abdominal discomfort, was reported. This meta-analysis demonstrates that a fixed dose at least 1 g of ginger is more effective than placebo for the prevention of postoperative nausea and vomiting and postoperative vomiting. Use of ginger is an effective means for reducing postoperative nausea and vomiting.