World-wide, total knee replacement (TKR) is a standard and definitive treatment option following failed adequate non-operative management of knee. After completing total knee replacement for the patients, it is necessary to assess the clinical and functional outcomes of the procedure. We have very few research-based information outcomes of total knee replacement. Aim of the study: The aim of to this study was to assess the clinical and functional outcomes of total knee replacement in patients with knee osteoarthritis. Methods: This prospective observational study was conducted in the Department of Orthopedics, Shaheed Ziaur Rahman Medical College, Bogura, Bangladesh during the period from March 2019 to December 2019. In total 37 patients with knee osteoarthritis attended and selected for total knee replacement in the mentioned hospital, maintained proper documentations were finalized as the study subjects. The outcomes of the patients were measured in terms of treatment excellent and good rate, incidence rate of complications, KSS, Hss, VAS and NRS scores. All data were processed, analyzed and disseminated by using MS Office and SPSS version 22 as per need. Results: In this study, the mean (±SD) Hss scores of pre and post TKR among the participants were 56.06±4.17 and 89.83±6.76 respectively. The mean (±SD) KSS scores of pre and post TKR among the participants were 54.17±5.27 and 85.79±8.32 respectively. The mean (±SD) VAS scores of pre and post TKR among the participants were 5.54±1.11 and 1.17±0.23 respectively. The mean (±SD) NRS scores of pre and post TKR among the participants were 5.44±1.05 and 1.25±0.33 respectively. In comparing all the scores between pre and post stages the P values were ‘<0.0001’. In analyzing the final outcomes among the participants, we observed that, 27.03%, 45.95%, 21.62% and 5.41% participants got ‘Excellent’, ‘Good’, ‘Acceptable’ and ‘Poor’ results respectively. Conclusion: Total knee replacement (TKR) significantly relieves pain of patients with knee osteoarthritis and ensures improves knee joint function with fewer complications. Considering the prompt healing, less complication and effectiveness of total knee replacement method physicians can take TKR as a prominent treatment option for the knee arthritis patients.