Objective To systematically evaluate the clinical effectiveness of platelet-rich plasma (PRP) combined with grafting material for the treatment of periodontal intrabony defects. Methods The following databases such as PubMed, The Cochrane Library, EMbase, CNKI, CBM and WanFang Data were searched on computer from inception to August, 2012 to collect the relevant randomized controlled trials (RCTs) on PRP combined with grafting material versus grafting material alone for periodontal intrabony defects. Two reviewers independently screened the literature according to the inclusion and exclusion criteria, extracted the data, and assessed the methodological quality of the included studies. RevMan 5.2 software was applied for meta-analysis. Results A total of 11 RCTs involving 342 patients were included. The pooled analysis on 7 RCTs showed that there was a significant difference in lower increase of clinical attachment loss (WMD=0.70, 95%CI 0.51 to 0.90, Plt;0.000 01) between the PRP combined with grafting material group and the grafting material alone group. But there was no significant difference in the gingival recession (WMD= −0.01, 95%CI −0.15 to 0.13, P=0.86). The pooled analysis on 9 RCTs showed that there was no significant difference in the reduction of plaque index (WMD= −0.04, 95%CI −0.09 to 0.02, P=0.20) between the two groups. Conclusion PRP combined with grafting material is superior to grafting material alone in the clinical attachment loss. But, there are no significant differences in gingival recession and plaque index. However, given the limited sample size and incomplete measure indexes of included studies, this conclusion still needs to be further proved by conducting more high-quality and large-scale RCTs.