Background: Total hip arthroplasty (THA) is a highly successful procedure for treating hip arthritis. However, subsidence of the femoral stem remains a concern, particularly in uncemented THA. Objectives: To evaluate the effects of immediate unrestricted weight-bearing on femoral stem subsidence and functional outcomes in patients undergoing unilateral uncemented THA. Methods: This prospective study included 20 patients who underwent unilateral uncemented THA. Patients were allowed full weight-bearing immediately after surgery. Femoral stem subsidence was measured radiologically, and functional outcomes were assessed using the Modified Harris Hip Score (MHHS) at preoperative and 6-week postoperative time points. Results: The mean age of the patients was 50.12 years, and 80% were diagnosed with avascular necrosis (AVN) of the femoral head. The mean postoperative femoral stem subsidence was 0.4mm. The MHHS showed significant improvement from a preoperative mean score of 37.0 ± 8.024 to a postoperative mean score of 82.1 ± 5.281 at 6 weeks. Conclusion: This study demonstrates that immediate unrestricted weight-bearing after unilateral uncemented THA is safe and effective, with minimal femoral stem subsidence and significant improvements in functional outcomes.