Anterior knee pain is one of the most frequent knee problems affecting physically active individuals. The reason for anterior knee pain has been suggested to be multifactorial with patella abnormalities or extensor mechanism disorder that leads to patellar malalignment during flexion and extension of the knee joint. Some patients complain primarily of non-specific knee pain, while others report patellar instability problems. The patients exhibit a variety of symptoms and clinical findings, which means that a thorough clinical examination is the key for optimal treatment. Weakness of the quadriceps muscle, especially during eccentric contractions, is usually present in the majority of anterior knee pain patients. However, irrespective of whether pain or instability is the major problem, hypotrophy and reduced activity of the vastus medialis are frequently found, which result in an imbalance between vastus medialis and vastus lateralis. This imbalance needs to be corrected prior to begninning quadriceps exercises. The non-operative rehabilitation protocol should be divided into different phases based on the patient’s progress. The goal of the first phase is to reduce pain and swelling, improve the balance between vastus medialis and vastus lateralis, restore normal gait, and reduce loading of the patello-femoral joint. The second phase should include improvement of postural control and coordination of the lower extremity, increase of quadriceps strength and when needed hip muscle strength, and restore good knee function. The patient should be encouraged to return to or to start with a suitable regular physical exercise. Therefore, the third phase should include functional exercises. Towards the end of the treatment, single-leg functional tests and functional knee scores should be used for evaluating clinical outcome. A non-operative treatment of patients with anterior knee pain should be tried for at least 3 months prior to the consideration of other treatment options.