Objective?To compare the effectiveness of P6 stimulation and sham stimulation/ drug intervention on prevention of postoperative nausea and vomiting (PONV). Methods?We searched PubMed (1990 to 2010), OVID (1990 to 2010), EBSCO (1990 to 2010), The Cochrane Library (1996 to 2010), PNAI (1990 to 2010), Hight Wirepres (1990 to 2010), and Chinese Digital Hospital Library (www.chkd.cnki.net) (1999 to 2010) to identify randomized controlled trials (RCTs) about P6 stimulation and sham stimulation/drug intervention on prevention of PONV. The methodological quality of the included studies was assessed and the data was extracted according to the Cochrane Reviewer’s Handbook 4.2.2. Meta-analyses were performed using RevMan 4.2 software. Results?A total of 21 studies were included. The results of meta-analyses indicated that: (1) Compared with sham stimulation, P6 stimulation could be effective in preventing postoperative nausea (beginning to termination) (Plt;0.000 01), postoperative early nausea (lt;after surgery 6 h) (P=0.000 6) and postoperative late nausea (gt;after surgery 6 h) (P=0.001). (2) Compared with sham stimulation, P6 stimulation could be effective in preventing postoperative vomiting (beginning to termination) (Plt;0.0.000 1) and postoperative early vomiting (P=0.002), but as to postoperative late vomiting (gt;after surgery 6 h), P6 stimulation had no effective preventive effect (P=0.08). (3) Compared with the drug intervention, P6 stimulation had little effect on preventing postoperative nausea (P=0.29) and vomiting (P=0.15). Conclusion?Compared with sham stimulation, P6 stimulation can be effective in preventing postoperative early nausea and vomiting as well as postoperative late nausea, but not effective in preventing postoperative late vomiting. In comparison with drugs, a large number of clinical trials are needed to prove P6 stimulation can replace drugs to prevent postoperative nausea and vomiting.