Anterior knee pain or patellofemoral pain syndrome is commonly encountered by clinicians, but the pathogenesis of this condition is not well understood. While much research has centred around the relationship between vastus medialis and anterior knee pain, little is known about the most lateral of the quadriceps muscle group, vastus lateralis (VL). Knowledge of the anatomical organization of VL is not only necessary to understand its precise function, but to also assist in the development of clinical and biomechanical models of knee dysfunction. The purpose of this study was to investigate the detailed morphology of VL, specifically to provide data relating to architecture, attachment sites, innervation, and the presence of anatomical partitioning within the muscle. The VL muscle was examined in 10 cadaveric lower limbs using macrodissection techniques. On the basis of architecture and innervation, this muscle comprised four partitions with each receiving its own unique nerve branch. The mean fascicular length of VL was 7 cm and the mean fascicular and muscle physiological cross-sectional areas were 1.2 cm2 and 21.6 cm2, respectively. In addition to inserting proximally at the base of the greater trochanter and distally into the superolateral border and base of the patella, three additional attachment sites were identified: the lateral intermuscular septum, iliotibial band, and the rectus tendon. The results of this study suggest that the gross morphology of VL is more complex than previously described, and the information provided regarding architecture will contribute to knowledge regarding the function of VL as well as its role in knee joint dysfunction. Clin. Anat. 23:575–585, 2010. © 2010 Wiley-Liss, Inc.