Patellofemoral pain syndrome is a descriptive term applied to patients with nonspecific anterior knee pain, and is the most common knee problem. The pain in most patellofemoral disorders is generalized to the anterior part of the knee. One important concept in patellofemoral joint function is the quadriceps angle (Q-angle). Theoretically, a higher Q-angle increases the lateral pull of the quadriceps femoris muscle on the patella and potentiates patellofemoral disorders. This study was undertaken to evaluate the relationship between the anterior knee pain and Q-angle.