Background: Osteoarthritis of the medial compartment of the knee in young, active individuals with intact range of motion is commonly treated with medial open wedge high tibia osteotomy (MOWHTO). Objective: The aim of the work was to use medial open wedge high tibial osteotomy to treat patients with medial compartment osteoarthritis and varus deformity improves their surgical outcomes. Patients and Methods: Twelve patients with varus deformity were treated by using MOWHTO performed in the period between 2020 and 2021 at Zagazig University Hospitals and El-Sahel Teaching Hospital. The age of the patients was ranged from 17 to 42 years. Eight males and four females completed the follow up period. Eight osteotomies were fixed using Puddu plate while the other four were fixed using Tomofix plate. Three osteotomies were performed with using bone graft while the others without using bone graft. Results: The time of union ranged from 9 to 24 weeks with a mean of 12.3 weeks. The mean period of pain relief among study subjects was eight months. All patients had full range of motion postoperatively except two who developed limited ROM due to pain after surgery and they restore full range of motion four months after surgery with physiotherapy. Conclusion: It could be concluded that for patients with medial compartment osteoarthritis 2ry to genu varus, MOWHTO is a good treatment as it restores the mechanical axis, relieves pain, improves motion and about 5 degrees valgus position is reached and thus redistribution of the load from medial compartment of the knee to lateral compartment.