Background: We aimed to evaluate the functional outcomes, incidence of bone tunnel laceration, and bone tunnel morphology of transosseous arthroscopic rotator cuff repair (ARCR) with the Arthro-TunnelerTM. Methods: Between May 2012 and April 2013, patients with full-thickness tears who underwent transosseous ARCR with the Arthro-TunnelerTM and could be followed for a minimum of 2 yr were included in this retrospective study. Functional outcomes, cuff repair integrity, intraoperative bone tunnel laceration, and postoperative bone tunnel morphology were analyzed. Results: We retrospectively evaluated 42 consecutive patients (average age: 67.6 yr) who underwent transosseous ARCR. The mean active forward elevation, mean active abduction, mean Constant-Murley score, mean American Shoulder and Elbow Surgeon Score (ASES), and pain Visual Analogue Scale (VAS) improved from preoperative values of 127 degrees, 118 degrees, 50.3 points, 53.2 points, and 4.5 to 159 degrees, 160 degrees, 83.3 points, 78.5 points, and 1.7, respectively, at the final follow-up (P<0.001, P<0.01, P<0.001, P<0.001, P<0.001, respectively). The re-tear rate was 16.7%. The intraoperative bone tunnel laceration occurrence was 67.8% (61 tunnels). Bone tunnel laceration and re-tear were significantly correlated. We evaluated the morphology of 81 bone tunnels with MRI of 90 bone tunnels. Eight, 37, and 36 tunnels were L-shaped, curve-shaped, and straight-shaped, respectively. Conclusions: The clinical results of transosseous ARCR with the Arthro-TunnelerTM were significantly improved at a minimum of 2 yr of follow-up. However, patients older than 65 yr were at a high risk of developing bone tunnel laceration, which was associated with rotator cuff re-tear.