Purpose: To compare the clinical and functional outcomes of the repair of an isolated type II SLAP lesion by 2 different configuration techniques (vertical v horizontal suture) through a single anterior portal. Methods: We designed a prospective, double-blinded, randomized clinical trial. A junior orthopaedic surgeon, who made the initial diagnosis, used a 10-point visual analog scale for pain and subjective instability and the American Shoulder and Elbow Surgeons (ASES) scoring system and evaluated the range of motion. After a diagnostic arthroscopy that ascertained the presence of an isolated type II SLAP lesion, patients were randomized to receive either vertical suture configuration (group 1) or horizontal suture configuration (group 2), both through a single anterior portal. Thirty-two patients were included in the study. The mean follow-up time was 37 months. Results: The mean postoperative ASES score was 91.9 in group 1 versus 95.8 in group 2 (P > .05). The differences observed from preoperative ASES score for both groups to postoperative ASES score were statistically significant. The differences observed in preoperative range of motion from the contralateral healthy shoulder and the affected shoulder in both groups were all clinically and statistically significant. Comparing the overall range of motion of the affected limb postoperatively with the range of motion of the contralateral healthy shoulder and between both groups, we found no statistically significant differences in forward flexion (P = .067), external rotation (P = .101), or internal rotation (P = .343). Conclusions: The results of this study suggest that the repair of an isolated type II SLAP lesion through a single anterior portal is clinically and functionally beneficial to patients regardless of the suture configuration performed (vertical or horizontal suture) because no differences were observed between these configurations after repair of an isolated type II SLAP lesion. Level of Evidence: Level I, randomized controlled trial. [Copyright &y& Elsevier]