The purpose of the present systematic review was to examine the efficacy of Acceptance and Commitment Therapy (ACT) applied to the treatment of social anxiety disorder (SAD). An exhaustive search was carried out in different databases. After the application of a number of inclusion and exclusion criteria, we included a total of eight studies conducted between 2005 and 2016 in our review. In three of these studies, ACT proved efficacious in reducing phobic symptoms and psychological inflexibility. The remaining five, which employed randomized controlled trials designs, showed that ACT and cognitive behavioral therapy (CBT) produced similar improvements both at post-treatment and during the follow-up. In some cases, ACT produced better treatment adherence and self-reported quality of life than CBT. All in all, all studies included in this paper reported improvements in TAS after ACT, in line with previous evidence. Results are discussed in terms of the strenghs and weaknesses of the evidence acumulated so far, and new directions for research are suggested.