Objectives: To investigate the overall effects of 12 weeks of yoga practice on chronic nonspecific lower back pain. Methods: PubMed, EMBASE, PsycINFO, Web of Science, and the Cochrane Library databases were searched from inception to February 9, 2019, and six randomized controlled trials were selected for this meta-analysis. Results: The pooled fixed-effect size of six trials showed that 12 weeks of yoga programs could significantly reduce chronic nonspecific lower back pain by 0.41 within the trials (standardized mean difference; 95% confidence interval: -0.58 to -0.23; p < .0001). Subgroup analyses also showed that significant pain reduction was related to type of yoga, length of session, study quality, and timing of pain assessment. Conclusions: These findings reveal that 12 weeks of yoga can help alleviate pain, and yoga programs should take into account the subgroup factors to increase individuals' relief from chronic nonspecific lower back pain.