Purpose <p>This study aimed to systematically review the literature comparing the structural integrity and clinical outcomes between delaminated and nondelaminated rotator cuff tears after <i>en masse</i> arthroscopic repair.</p> Methods <p>A systematic review of the literature was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A literature search was performed in the electronic databases of PubMed, EMBASE, and the Cochrane Library for published studies reporting clinical and imaging outcomes after surgical repair of tears. Only English-language studies were included.</p> Results <p>Seven comparative studies were assessed in this review, including 882 (44.5%) shoulders for the delaminated group and 1099 (55.5%) shoulders for the nondelaminated group. For the delaminated and nondelaminated groups, the mean ages were 61.7 and 59.8 years, respectively. The results show a significantly higher rate of complete healing rate in nondelaminated tendons than in delaminated tendons after <i>en masse</i> arthroscopic repair (risk ratio, 0.86; 95% CI, 0.80 to 0.93; <i>p</i> &lt; .0001). Furthermore, pooled data show that partial healing and retear rate are lower in nondelaminated cuff tears than in delaminated tears after arthroscopic repair [(risk ratio, 1.63; 95% CI, 1.26 to 2.10; <i>p</i> = .0002; risk ratio, 1.81; 95% CI, 1.40 to 2.33; <i>p &lt;</i> .00001), respectively]. In addition, functional outcome scores showed no significant difference between both groups.</p> Conclusion <p>Delaminated tendon tears exhibit poorer complete healing and higher retear rates following <i>en masse</i> repair compared with nondelaminated tears. However, delamination does not appear to influence patient-reported outcome scores or postoperative range of motion.</p>