The patellofemoral joint experiences substantial physiologic loads with normal daily activity. Anatomic risk factors can place certain patients at risk for patellofemoral pathology including patellar instability. Stability and load capacity of the joint are a result of numerous factors including the unique configuration of osseous and cartilaginous structures, static and dynamic soft tissue stabilizers, and global lower limb alignment. A thorough understanding of the anatomy and biomechanics of the patellofemoral joint is required to identify patient-specific sources of dysfunction and to tailor individualized treatment specific to a given patient's anatomy. Our understanding of this pathology continues to evolve with improvement in anatomical knowledge, new technologies for biomechanical evaluation, and advanced imaging modalities. The purpose of the present review is to provide an updated anatomic and biomechanical overview pertinent to patellar instability.