BACKGROUND: Patients with recurrent lateral patellar dislocations are often treated with reconstruction of the medial patellofemoral ligament (MPFL). PURPOSE: To perform a systematic review to evaluate clinical outcomes and the risk of recurrent patellar dislocation after MPFL reconstruction (MPFLR) with autograft versus allograft. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: The authors conducted a search of PubMed, the Cochrane Library, and Embase to identify studies comparing outcomes of MPFLR with autograft versus allograft. The inclusion criteria were full-text studies that directly compared clinical outcomes and/or risk of recurrent patellar instability between patients undergoing MPFLR with autograft versus allograft. A quality assessment was performed using the modified Coleman Methodology Score, and risk-of-bias assessment was performed using the Risk Of Bias In Non-randomized Studies-of Interventions and the Cochrane Collaboration tools. RESULTS: Seven studies (1 evidence level 2, 3 level 3, 3 level 4) that met inclusion criteria were identified and included a total of 150 patients who underwent MPFLR with autograft and 193 with MPFLR with allograft. One study found a significantly higher failure rate among patients with autograft, and another study found a trend toward a significantly higher failure rate among patients with autograft. One study demonstrated no significant difference between postoperative tibial tubercle-trochlear groove distance (measured on magnetic resonance imaging scans) in failed versus successful grafts. One study found that patellar tilt angle improved significantly from preoperatively to postoperatively (P < .001) but there was no difference between the groups. Kujala scores significantly improved for both autograft and allograft groups across studies. Two studies found significant differences in postoperative Kujala scores between the 2 groups, 1 of which found better scores in the allograft group (P = .0032) and another in which scores were better in the autograft group (P = .02). CONCLUSION: Patients undergoing MPFLR with either autograft or allograft can expect to experience improvement in clinical outcomes. Subjective outcomes improved to a similar degree in both groups. Graft failure was more frequently observed in patients with autograft. Allograft may be a better option for MPFLR owing to lower failure rate.