Background: Osteoarthritis (OA) is a common degenerative disease in elderly people, OA of the knee (KOA) makes up for a big part of all OA cases. Common KOA inconveniences are joint stiffness, pain and loss of muscle strength, which can have a negative impact on the quality of life. The OA process affects the kinematics of the knee joint and increases joint laxity, an impairment which can create more damage to the knee joint. Conservative treatment including exercise is the first option of choice in rehabilitation. Manual joint mobilization is another common treatment method which has effect on function and pain in patients with KOA. One muscle located in the hollow of the knee is the popliteal muscle and its function is to internally rotate the tibia, flex the knee joint and reduce ventral translation of the tibia; popliteal activity aims to maintain proper knee kinematics. Purpose: To investigate what effect myofascial release and exercise for the popliteus muscle have regarding pain, function and health related quality of life in people suffering from KOA. Method: A single subject experimental design study consisting of three participants with KOA was performed. The study started with a baseline phase measurement where the participants answered questionnaires about their pain, function and quality of life, followed by the intervention phase consisting of myofascial release (MFR) and exercise for the popliteal muscle. Result: There was not any concordant results for any of the outcome measurements even though each participant had positive changes in one or more of the different measurements mainly regarding pain, function in daily living or quality of life (QoL). Conclusion: MFR and exercise for the popliteus muscle might be effective as a treatment for people with KOA related inconveniences regarding mainly pain, function in daily living and QoL. Key words: Knee osteoarthritis, myofascial release, exercise, popliteus muscle.