Yoga has become a popular form of CAM and is often advocated for a wide range of conditions. The aim of this overview was to evaluate critically all systematic reviews of yoga for the symptomatic treatment of any condition. Twelve electronic databases were searched and 21 systematic reviews relating to a wide range of conditions were located. Nine systematic reviews arrived at positive conclusions, but many systematic reviews were associated with a high risk of bias. Unanimously positive evidence emerged for depression and cardiovascular risk reduction. Despite an impressive number of systematic reviews, evidence of effectiveness is positive only for two indications.