Patellofemoral problems, a common cause of anterior knee pain which an orthopaedist or a sports physician usually see, is defined as `the black hole of the orthopaedics`, implying the lack of any consensus on the diagnosis and treatment of these problems. A wide range of classification systems have been developed for this clinical entity in which athletes suffer due to usually an overuse activity. In this review, patellofemoral problems seen in the athletes are classified to adress the clinicians for the diagnosis and treatment. The pathophysiology and origin of the problem should be examined to decide the most effective treatment modality and individual characteristics of the patients should be also considered.