Background:Although isolated posterior cruciate ligament reconstruction (PCLR) has become a more frequently performed procedure, reports of functional outcomes and return-to-sport (RTS) rates to support its use are still limited. Purpose:To systematically review the literature to determine the rates of RTS and the functional outcomes of patients after isolated PCLR. Study Design:Systematic review: Level of evidence, 4. Methods:Two reviewers independently searched 5 databases for patient-based clinical studies with a minimum 2-year follow-up that analyzed functional outcome and RTS following isolated PCLR. Studies with multiligament knee reconstruction were excluded. Risk of bias was performed with a modified Downs and Black checklist. The primary outcomes were Tegner and Lysholm scores, rates of RTS, and International Knee Documentation Committee (IKDC) subjective scores. Secondary outcomes were IKDC objective scores, instrumented knee laxity assessment, and Telos radiographic analysis. Where feasible, these data were pooled via a random effects meta-analysis model. Results:Of the 240 titles identified, 14 studies were included. The median time from injury to surgery was 10.6 months (range, 6 weeks-21 years). The pooled mean postoperative Tegner and Lysholm scores were 5.7 (95% CI, 5.4-6.0) and 87.8 (95% CI, 85.6-90.0), respectively, following isolated PCLR; the pooled effect size between pre- and postoperative values was 2.8 (95% CI, 1.6-4.0) and 3.7 (95% CI, 2.6-4.9), respectively. An RTS rate of 44% (95% CI, 23%-66%) was identified. IKDC subjective scores improved to a pooled mean of 73.5 (95% CI, 62.8-84.1), with an effect size of 3.0 (95% CI, 0.4-5.6). The proportion of patients with postoperative IKDC objective scores of grade A/B was 82%. The pooled postoperative KT-1000/KT-2000 side-to-side difference was 3.4 mm (95% CI, 2.5-4.3 mm), with an effect size of 2.8 (95% CI, 1.1-4.5). The pooled postoperative Telos side-to-side difference measurement was 3.5 mm (95% CI, 2.8-4.3 mm), with an effect size of 3.9 (95% CI, 3.3-4.5). Conclusion:The results of this review demonstrate that while isolated PCLR results in a significant improvement in functional outcome scores and improved knee laxity, there is a low rate of return to preinjury level of sport. The prolonged period from injury to surgery might reduce functional improvement and RTS following reconstruction. Therefore, comparison of the outcomes of isolated PCLR and nonoperative treatment is impracticable owing to the potential for selection bias.