BACKGROUND: The trial aimed to prospectively compare the functional outcomes of patients undergoing arthroscopic rotator cuff repair using transosseous-equivalent double-row (TEDR) or single-row (SR) suture anchor techniques at 3 years postoperatively for both large (>3 cm) and small (<3 cm) tears. METHODS: Eighty patients with a symptomatic and magnetic resonance imaging (MRI)-proven full-thickness rotator cuff tear, who had failed conservative management of at least 6 months' duration and who had a complete passive range of motion of the affected shoulder, were enrolled in the trial. Patients were randomized to TEDR repair (n = 40) or SR repair (n = 40). Subgroup analysis was conducted for tears <3 cm (TEDR n = 17, SR n = 19) and tears >3 cm (TEDR n = 23, SR n = 21). Primary outcomes included the Oxford Shoulder Score (OSS), the University of California, Los Angeles (UCLA) score, and the Constant-Murley score (CMS). The secondary outcomes included a 0-100-mm visual analog scale (VAS) score for pain, range of motion (ROM), and EQ-5D scores. All patients completed a follow-up of 3 years. RESULTS: There was a significant difference in the mean OSS postoperative score for tears >3 cm (P = .01) and mean improvement from baseline in the TEDR group (P = .001). For tears >3 cm, mean postoperative scores were also significantly higher in the TEDR group for UCLA (P = .015) and CMS (P = .001). Post hoc testing showed that the differences between these groups was statistically significant (P < .05). For tears <3 cm, a significant postoperative difference in favor of SR repair was seen in the mean CMSs (P = .011), and post hoc testing showed that the difference was statistically significant (P = .015). No significant difference was seen with mean postoperative OSS or UCLA, and post hoc testing did not show a statistically significant difference between groups. CONCLUSIONS: TEDR repair showed improved functional outcomes for tears >3 cm compared with SR repair. For tears <3 cm, no clear benefit was seen with either technique.