Objective: This study aimed to compare the effects of 24-h continuous femoral nerve block (CFNB) and periarticular infiltration analgesia (PIA) on postoperative pain and functional results in the first 6 weeks after total knee arthroplasty (TKA). Methods: Sixty patients who underwent unilateral TKA were included in this study. The patients were divided into two groups: Group A received CFNB and Group B received PIA. Each patient received 0.25% levobupivacaine and 1:100,000 epinephrine as infiltration to the posterior capsule. A patient-controlled analgesia (PCA) device was used for all patients, and 24-h tramadol usage by patients was recorded. We measured maximum range of motion (ROM), pain using a visual analog scale (VAS), 2-min walk test (2MWT), and the scores of Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Knee Society Score (KSS). Results: Compared with Group B, Group A had lower postoperative opioid usage (p<0.05), less pain at rest (p<0.05), less pain with passive motion (p<0.05), less pain with movement and after active movement (p<0.05), and superior passive and active ROM (p<0.05). Group A also had better 2MWT results at 24 and 48 h after surgery (p<0.05), and superior WOMAC and KSS results at 6 weeks after surgery. Conclusion: As long as it is applied with infiltration analgesia to the posterior capsule, CFNB is an effective and safe analgesia method resulting in better postoperative patient comfort and greater ROM. Furthermore, it produces better results in the early postoperative period with a favorable side effect profile.