Introduction: Osteoarthritis (OA) is a chronic degenerative intra-articular disorder of cartilage and bone. Knee joint is most commonly involved due to its pivotal role in weight bearing as it is constantly exposed to wear and tear. Osteotomy procedures can achieve normal alignment of the weight bearing axis of the lower limbs. Aim: To evaluate and compare the functional outcome of High Tibial Osteotomy (HTO) and Proximal Fibular Osteotomy (PFO) in medial compartmental osteoarthritis of knee joint. Materials and Methods: This prospective longitudinal study was conducted in a tertiary healthcare centre, IPGMER and SSKMH, Kolkata,West Bangal, India from October 2019 to November 2021 for a duration of 26 months, in which 40 osteotomies were performed around the knee. Considering the inclusion and exclusion criteria 20 proximal fibular osteotomies and 20 high tibial osteotomies were operated avoiding the patients with advanced stage or tricompartmental OA. The scoring system considered for evaluation of the functional outcome was Oxford Knee Score (OKS) and Visual Analouge Scale (VAS) Score. The analysis was done through paired t-test with determining of p-value where value ≤0.05 was considered for statistically significant. Results: Majority of the patients in the present study were more than 45 years of age. The most frequent age group was 46-50 years followed by 51-55 years. The follow-up period was at least 15 months where the OKS score was 39.35±3.51 and 41.20±4.50 with p-value of 0.1556 and VAS score was 5.50±1.10 and 3.80±1.10 with p value of <0.0001 for PFO and HTO respectively. Only two of the patients developed surgical site infection in both cases. Conclusion: In long term follow-up the final functional status of both treatment modalities were comparable although HTO was considered superior with significant improvement in pain relief perspective than PTO.