Objective To assess the effectiveness of sternocleidomastoid muscle (SCM) flap in preventing gustatory sweating syndrome following parotidectomy. Methods Databases including The Cochrane Library, MEDLINE, EMbase, CBM, CNKI, VIP and WanFang Data were searched from inception to March 2012 to retrieve randomized controlled trials (RCTs) about SCM flap in preventing gustatory sweating syndrome following parotidectomy. The data of studies meeting the inclusion criteria were extracted by two reviewers independently, the methodological quality was assessed and cross-checked, and meta-analysis was performed using the RevMan 5.1 software. Results A total of 10 RCTs involving 825 patients were included. The results of meta-analyses showed that compared with the blank control group, SCM flap could obviously decrease the subjective incidence of gustatory sweating syndrome by 78% (OR=0.22, 95%CI 0.08 to 0.59, P=0.003) and the objective incidence by 83% (OR=0.17, 95%CI 0.05 to 0.60, P=0.006). The sensitivity analysis indicated the above results were robust. The evidence based on GRADE system was of “low quality”. There was no obvious publication bias according to the tunnel chart. Conclusions Current evidence shows that SCM flap can obviously decrease both subjective and objective incidence of gustatory sweating syndrome following parotidectomy. Considering the limitation of the included studies, this conclusion still needs to be tested by more large-scale and high-quality RCTs taking SCM function as one of the outcome.