Individuals with knee osteoarthritis, a painful debilitating joint disease affecting many aging adults, are commonly encouraged to pursue a variety of exercise regimens. However, very few studies have specifically focused on barriers and facilitators of exercise adherence as related to knee osteoarthritis. This review focuses on what is known about exercise adherence, as well as those factors that influence exercise adherence, both generally, and in the context of knee osteoarthritis. To this end, a wide array of related studies were retrieved and reviewed. The objective was to better understand the relationship between this disabling health condition and exercise, and factors that might specifically determine long-term exercise participation among this population. Results of this search revealed: 1) strong support for the application of exercise to allay the progression and/or severity of knee osteoarthritis and its consequences, but poor adherence rates in reality; 2) a vast array of disease-associated, as well as other exercise adherence barriers; 3) many recommendations for promoting exercise adherence including improving the nature of the patient-provider relationship, and the importance of individualized exercise prescriptions. It is concluded that life-long exercise is crucial for maximizing the well-being and function of adults with knee osteoarthritis, but recommendations to exercise are often pursued inconsistently. To encourage exercise adherence among this cohort, a comprehensive individualized assessment, active patient involvement in the decision-making process, and long-term monitoring are indicated.