Objective: To evaluate the quality of evidence and the strength of recommendation for yoga as an ancillary intervention in rheumatic diseases. Methods: Medline/PubMed, Scopus, the Cochrane Library and IndMED were searched through February 2013. Randomized controlled trials (RCTs) comparing yoga with control interventions in patients with rheumatic diseases were included. Two authors independently assessed the risk of bias using the Cochrane Back Review Group risk of bias tool. The quality of evidence and the strength of the recommendation for or against yoga were graded according to the GRADE recommendations. Results: Eight RCTs with a total of 559 subjects were included; two RCTs had a low risk of bias. In two RCTs on FM syndrome, there was very low evidence for effects on pain and low evidence for effects on disability. In three RCTs on OA, there was very low evidence for effects on pain and disability. Based on two RCTs, very low evidence was found for effects on pain in RA. No evidence for effects on pain was found in one RCT on CTS. No RCT explicitly reported safety data. Conclusion: Based on the results of this review, only weak recommendations can be made for the ancillary use of yoga in the management of FM syndrome, OA and RA at this point. Keywords: carpal tunnel syndrome; complementary therapies; fibromyalgia; osteoarthritis; review; rheumatoid arthritis; rheumatology; yoga.