Knowledge of the exact location of the distal biceps brachii insertion is crucial when performing tendon reconstruction or repair. To quantitatively describe the morphology of the distal biceps brachii insertion, 20 cadaveric arms were examined. Linear and angular measurements, including the footprint dimensions and shape, radial tuberosity dimensions and irregularities, and the rotational position of the tuberosity and footprint, were obtained. The axial and transverse dimensions of the radial tuberosity and distal biceps tendon footprint measured 24.2 x 12 mm and 18.7 x 3.7 mm, respectively. The insertion footprint is on the posterior/ulnar aspect of the radial tuberosity centered at approximately 30 degrees anterior to the lateral/coronal plane with the forearm fully supinated. This explains why any preoperative limitation in supination may make an anatomic repair difficult through a single anterior incision. To our knowledge, this is the first study to quantitatively describe the angular location of the radial tuberosity and the relationship of the distal biceps tendon on the tuberosity.