Context: Recent studies have demonstrated that physical activity is well tolerated by patients with idiopathic inflammatory myopathies (IIMs) and can have additional benefits as an adjuvant therapy to pharmacologic agents, especially if started early. To date, no studies have examined the effects of yoga on patients with IIMs. Aims: The aim of this study was to evaluate the effects of yoga on self-reported difficulty in performing activities of daily living (ADL) and muscle strength in patients with mild-to-moderate IIMs. Subjects and Methods: A longitudinal cohort study in which participants were assessed using the Myositis Activities Profile (MAP) and manual muscle testing (MMT) before and after the completion of an 8-week instructor-guided yoga course was performed. Statistical Analysis Used: Wilcoxon signed-ranked test was performed for statistical analysis. Results: The average posttreatment MAP scores of six participants demonstrated an increase of 2.51 points, while the average MMT score of four participants demonstrated an increase of 11 points. Conclusions: This study is the first study to date to examine the effect of yoga as an adjuvant complementary therapy for patients with IIM. Continued research should be done on the effect of yoga as an adjuvant therapy, for in addition to increase in muscle strength and ability to perform ADL, yoga may offer potential improvements in mood, mental health, and sleep.