Purpose To compare clinical outcomes of knotted and knotless single-suture bridge techniques in the arthroscopic treatment of bursal-sided rotator cuff tears.Methods Patients with bursal-sided tears were analyzed from June 2017 to March 2019; 54 patients were repaired using the knotted single-suture bridge technique (KT group), 59 patients with the knotless single-suture bridge technique (KLT group). All patients were followed up for a minimum of 24 months (in the range 24–35 months). The shoulder range of motion, and visual analog scale (VAS) score data were collected before operation, at three weeks, at three and six months after operation, and at the last follow-up. Meanwhile, American Shoulder and Elbow Surgeons (ASES) score and Constant–Murley (CS) shoulder score were collected before operation and at the last follow-up. Rotator cuff healing was evaluated by Barth ultrasonic classification at the last follow-up.Results At the last follow-up, VAS score had decreased from 5.0 (3.8, 6.0) to 0.0 (0.0, 1.0) in the KT group and from 5.0 (4.0, 6.0) to 0.0 (0.0, 0.0) in the KLT group. VAS score was higher in the KT group than in the KLT group at four postoperative time points. At three and six months after surgery, the patients in the KLT group had better anterior flexion and internal rotation than the KT group. Meanwhile, at the last follow-up, the internal rotation in the KLT group was still better than that of the KT group (P = 0.023), and the postoperative ASES score in the KLT group(97.90 ± 1.84) was significantly higher than that in the KT group(94.10 ± 3.18) (P = 0.001). Finally, there were two cases of retear in the KT group, and one case of retear in the KLT group, with no statistically significant difference (P = 0.938). At the final follow-up, healing was better in the KLT group by Barth ultrasonic classification (P = 0.019).Conclusions The knotless single-suture bridge technique maybe can result in more obvious pain relief, better anterior flexion and internal rotation range of motion, and functional recovery of the shoulder joint in the early stages. Also, healing may be better under ultrasound classification with the knotless single-suture bridge technique.Level of evidence: Level III; Retrospective Cohort Study; Treatment Study