OBJECTIVE: To compare the clinical efficacy of anterior and posterior approaches for selective thoracic fusion (STF) and selective thoracolumbar/lumbar fusion (SLF) in treating adolescent idiopathic scoliosis (AIS). METHODS: English-language literature on selective fusion treatment of AIS published before September 2016 was retrieved from the PubMed, Embase, Cochrane, and Google Scholar databases. Studies were manually selected for inclusion based on preset criteria. Relevant radiologic data were extracted, and a systematic review and meta-analysis were performed. RESULTS: Thirty-five eligible studies were included. The Cobb angles of the main thoracic and minor thoracolumbar/lumbar curves at the final follow-up were significantly and similarly corrected in the anterior and posterior STF groups. Anterior but not posterior STF was effective in correcting thoracic and thoracolumbar junctional hypokyphosis and in promoting sagittal balance, as determined by the relative position of the C7 plumb line. Similarly, in both the anterior and posterior SLF groups, the final Cobb angles of main thoracolumbar/lumbar and minor thoracic curves were significantly reduced compared with angles before surgery (P < 0.05). In contrast, posterior but not anterior SLF was effective in correcting lumbar hypolordosis and thoracic hypokyphosis. Both anterior and posterior SLF promoted coronal balance, with no effects on sagittal balance. CONCLUSIONS: Both anterior and posterior approaches are effective for treatment of AIS. Anterior is more effective than posterior STF in correcting thoracic and thoracolumbar junctional hypokyphosis and in restoring sagittal balance. Posterior is more effective than anterior SLF in correcting lumbar hypolordosis and thoracic hypokyphosis and in restoring the sagittal curvature.