ABSTRACT: Osteoarthritis (OA) is a common problem in older women that is associated with pain and disabilities. Although yoga is recommended as an exercise intervention to manage arthritis, there is limited evidence documenting its effectiveness, with little known about its long term benefits. This study's aims were to assess the feasibility and potential efficacy of a Hatha yoga exercise program in managing OA-related symptoms in older women with knee OA.Eligible participants (N=36; mean age 72 years) were randomly assigned to 8-week yoga program involving group and home-based sessions or wait-list control. The yoga intervention program was developed by a group of yoga experts (N=5). The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score that measures knee OA pain, stiffness, and function at 8 weeks. The secondary outcomes, physical function of the lower extremities, body mass index (BMI), quality of sleep (QOS), and quality of life (QOL), were measured using weight, height, the short physical performance battery (SPPB), the Pittsburgh Sleep Quality Index (PSQI), the Cantril Self-Anchoring Ladder, and the SF12v2 Health Survey. Data were collected at baseline, 4 weeks and 8 weeks, and 20 weeks.The recruitment target was met, with study retention at 95%. Based on ANCOVAs, participants in the treatment group exhibited significantly greater improvement in WOMAC pain (adjusted means [SE]) (8.3 [.67], 5.8 [.67]; p=.01), stiffness (4.7 [.28], 3.4 [.28]; p=.002) and SPPB (repeated chair stands) (2.0 [.23], 2.8 [.23]; p=.03) at 8 weeks. Significant treatment and time effects were seen in WOMAC pain (7.0 [.46], 5.4 [.54]; p=.03), function (24.5 [1.8], 19.9 [1.6]; p=.01) and total scores (35.4 [2.3], 28.6 [2.1]; p=.01) from 4 to 20 weeks. Sleep disturbance was improved but the PSQI total score declined significantly at 20 weeks. Changes in BMI and QOL were not significant. No yoga related adverse events were observed.A weekly yoga program with home practice is feasible, acceptable, and safe for older women with knee OA, and shows therapeutic benefits.ClinicalTrials.gov: NCT01832155.