Background and Objective: Reconstruction of the anterior cruciate ligament (ACL) simultaneously with medial unicompartmental knee arthroplasty (UKA) has been suggested as an alternative treatment in patients with ACL deficiency and localized osteoarthritis (OA) in young patients. The objectives of this review were to report the current concepts on the topic and describe an original surgical technique of simultaneous medial UKA and ACL reconstruction. Methods: A literature search was performed on PubMed, including articles written in English until June 2021. The articles regarding ACL reconstruction and UKA were reviewed using the narrative approach. Inclusion criteria: (I) original articles about ACL reconstruction and unicompartmental knee replacement; (II) written in English; (III) involving three or more cases. Two non-blinded authors reviewed the titles and abstracts of each article identified in the literature search. Key Content and Findings: The articles regarding ACL reconstruction and UKA were reviewed using the narrative approach. Conclusions: There is controversial evidence about performing the UKA simultaneously with an ACL reconstruction. Biomechanical and clinical studies show that the benefits of restoring good joint stability outweigh the possible risks associated with performing both surgeries at the same time. With this strategy, it is possible to obtain good clinical results with a high survival rate of the implant and patient satisfaction.