BACKGROUND: Closed kinetic chain (CKC) exercises are the gold standard for rehabilitation after anterior cruciate ligament reconstruction (ACL-R). Open kinetic chain (OKC) exercises may provide benefits, but their use in the early stages remains controversial. OBJECTIVE: To determine the effect of OKC exercises during the first weeks of rehabilitation after ACL-R. STUDY DESIGN: Systematic review and meta-analysis. METHODS: A comprehensive literature search was conducted according to PRISMA guidelines from inception to April 2024. The methodological quality of the included studies was assessed using the ROBINS I and RoB-2 tools. The changes in outcomes from pre-to post-intervention were quantified using standardized mean differences. RESULTS: Overall, the methodological quality was low and the population, intervention, comparison, outcome, time (PICOT) criteria were heterogeneous. However, OKC was found to have beneficial effects on patient reported outcomes (PROMs), strength, function, and return to play, especially when performed at least four weeks after surgery in rehabilitation programs that began with CKC exercises. CONCLUSION: The evidence suggests that OKC exercises may provide benefits and no adverse effects in the early stages of rehabilitation after ACL-R, particularly when initiated after CKC exercises. These findings are consistent with current clinical practice guideline recommendations for the inclusion of OKC in rehabilitation programs.