The aim of this study was to examine the efficacy of Kundalini Yoga in reducing symptoms of generalized anxiety disorder (GAD) compared to a common treatment-as-usual condition using cognitive techniques. A secondary objective was to explore potential treatment mechanisms. Females aged 24 to 75 years with GAD (n = 49) received either an 8-week Kundalini Yoga intervention (n = 34) or an 8-week treatment-as-usual condition (n = 15). The yoga condition resulted in lower levels of anxiety relative to the treatment-as-usual condition. Furthermore, changes in somatic symptoms mediated treatment outcome for Kundalini Yoga. Kundalini Yoga may show promise as a treatment for GAD, and this treatment might convey its effect on symptom severity by reducing somatic symptoms.