Anterior knee pain is a common musculoskeletal complaint seen by primary care providers. It describes a large spectrum of clinical entities whose predominant symptoms include pain from the patellofemoral joint and surrounding structures. The term “anterior knee pain” can be used to describe primary painful syndromes as well as pain secondary to instability of the patellofemoral articulation. This chapter focuses on diseases such as patellofemoral syndrome, the most common cause of anterior knee pain seen in primary care settings, as well as other entities such as bursitis, septic and inflammatory arthritis, patellar tendinopathy, and Osgood- Schlatter disease. It discusses painful syndromes of the patellofemoral joint. The term patellofemoral syndrome is used to encompass all the pain-causing problems of this joint except those secondary to instability. It is imperative to determine the exact etiology of anterior knee pain to develop a precise and effective treatment protocol.