Treatment for unicompartmental knee osteoarthritis (OA) is controversial in young patients with concomitant anterior cruciate ligament (ACL) deficiency. The aim of the current study is to report long-term results after the combination of unicompartmental knee arthroplasty (UKA) and ACL reconstruction. Retrospective study of one-stage medial UKA and ACL reconstruction was performed on eight patients at a mean age of 52 years (42-60). Clinical and radiological results were assessed and analyzed after a mean follow-up of 14.6 years. Patients were satisfied and mean personal satisfaction rate was 8.8 (4-10). At the last follow-up, mean WOMAC score was 26 (1-52) and mean global KSS was 154 (102-200). One revision surgery to total knee arthroplasty was performed 9 years after the combined procedure due to aseptic loosening. One more case of clinical deterioration was observed 13 years after index surgery. Combined UKA and ACL reconstruction can be a therapeutic option for young and active patients with concomitant knee instability and unicompartmental OA. The procedure is highly demanding and reliable only in hands of experienced surgeons. Overall, satisfactory outcome can be achieved at a minimum follow-up of 10 years. However, clinical deterioration can be observed in the long term.