Objectives: Both arthroscopic and open surgical techniques are commonly utilized for proximal biceps tenodesis of the long head of biceps brachii. One concern about the arthroscopic approach is that a portion of the biceps tendon may remain in the bicipital groove, which is a possible source of persistent post-operative pain.  The purpose of this study was to determine the location of tendon fixation in an open subpectoral technique and an arthroscopic technique that attempted to place the biceps inferior to the bicipital groove. The null hypothesis was that there would be no difference in the tenodesis site for the arthroscopic and open techniques. Methods: With the shoulders in a beach chair position, ten matched pairs of cadaver shoulders were randomized such that within each pair one shoulder underwent a standard open subpectoral biceps tenodesis and the other underwent an arthroscopic tenodesis. The arthroscopic technique was performed through an anterior working portal directly over the tendon with the arm forward flexed and the arthroscope in a standard lateral portal. Following the procedures, specimens were carefully dissected and the distances from pertinent anatomic landmarks to the tunnel were measured with a digital caliper. AP and lateral radiographs were also obtained, and radiographic measurements were conducted using a PACS measurement system in line with the longitudinal axis of the humerus. Paired T-tests were used to compare open versus arthroscopic results. Results: Anatomy: Measurements from the superior border of the bicipital groove to the tenodesis tunnel averaged 32.2 +/- 9.8 mm distal for the arthroscopic technique and 54.8 +/- 8.4 mm distal for the open technique (p<0.001). (Figure 1, Table 1) The distance from the inferior border of the bicipital groove to the tenodesis tunnel averaged 9.8 +/- 8.6 mm distal for the arthroscopic technique and 32.8 +/- 7.8 mm distal for the open technique (p<0.001). The distance from the superior border of the latissimus dorsi to the tenodesis tunnel averaged 2.7 +/- 9.0 mm distal for the arthroscopic technique and 24.2 +/- 7.4 mm distal for the open technique (p<0.001). Radiography: On radiographic assessment, the distance from the junction of the greater tuberosity and the humeral head articular surface to the tenodesis tunnel measured 33.5 +/- 7.5 mm distal for the arthroscopic technique and 54.3 +/- 6.5 mm distal for the open technique (p<0.001). The distance from the most medial aspect of the lesser tuberosity to the tenodesis tunnel measured 16.6 +/- 8.4 mm distal for the arthroscopic technique and 37.5 +/- 6.0 mm distal for the open technique (p<0.001). Conclusion: This study found that the open subpectoral technique for proximal biceps tenodesis placed the tenodesis tunnel significantly further distal than the arthroscopic technique, generally about 2 cm. The arthroscopic technique did, however, always place the tunnel below the bicipital groove, and even below the superior border of the latissimus dorsi in most cases. This may allay concern about the bicipital groove as a pain source using this arthroscopic technique. The radiographic findings were consistent with the anatomic findings.