Osteoarthritis (OA) is a chronic joint disease that affects more than one-third of older adults (age > 65 years), most often involving the hip and knee. Osteoarthritis causes pain and limits mobility, thereby reducing patient quality of life. Conservative, nonsurgical, nonpharmacologic treatment strategies include weight reduction, orthotics, physical therapy modalities, acupuncture, massage, and exercise. The breadth of the current literature on OA can make determining the appropriate exercise prescription challenging. Aerobic exercise, strengthening exercise, Tai chi, and aquatic exercise can all alleviate pain and improve function in patients with OA. The choice of the specific type and mode of delivery of the exercise should be individualized and should consider the patient's preferences. Ongoing monitoring and supervision by a health care professional are essential for patients to participate in and benefit from exercise.