Study Design Controlled, cross-sectional laboratory study. Background Despite the growing popularity of yoga, little is known about the muscle activity of the scapular stabilizers during isometric yoga postures and their potential utility in shoulder rehabilitation. Objectives To examine scapular stabilizer muscle activation during various yoga postures. Methods Twenty women with yoga experience and no shoulder pain or injury participated. Electromyography was used to record the muscle activity of the upper, middle, and lower trapezius, as well as of the serratus anterior, during 15 yoga postures. Results Muscle activity varied between yoga postures (3%-57% maximum voluntary isometric contraction [MVIC]). Overall, the "locust arms forward" posture elicited the highest activity from the upper (22.4% MVIC), middle (41.8% MVIC), and lower (56.8% MVIC) trapezius, while several postures elicited moderate activity (greater than 20% MVIC) from the serratus anterior. Conversely, the "dancer's pose right," "reverse tabletop," and "warrior II" postures demonstrated low activity (less than or equal to 15.7% MVIC) of the scapular stabilizers. Conclusion Strengthening the scapular stabilizer muscles is an important component of shoulder rehabilitation. Yoga postures have been identified that activate the scapular stabilizer muscles at varying levels of activity. J Orthop Sports Phys Ther 2018;48(6):504-509. Epub 6 Apr 2018. doi:10.2519/jospt.2018.7311.