Patellofemoral pain syndrome (PFPS) is a common musculoskeletal condition. Although quadriceps strengthening is widely used in the treatment of PFPS, a 2003 review found reduced evidence supporting its use. Since then, various studies on this topic were published, and thus an updated review was performed. This systematic review found strong evidence for the use of quadriceps strengthening exercises, alone or with other interventions, in the treatment of patellofemoral pain syndrome.