Purpose: We examined and compared the daily step counts and health-related quality of life of patients before undergoing either bilateral or unilateral (with or without arthritis in the opposite joint) total hip arthroplasty (THA), and for 6 months afterwards.Participants and Methods: Participants were patients who were living at home and were requested to wear accelerometers and log their daily step count preoperatively and again 6 months postoperatively. Additionally, they completed the Oxford Hip Score and EuroQol 5-Dimension questionnaires at both time points.Results: Data from 40 patients were analyzed. Patients underwent bilateral total hip arthroplasty (n=13), unilateral total hip arthroplasty with arthritis in the opposite joint (n=13), and unilateral total hip arthroplasty without arthritis in the opposite joint (n=14). The Oxford Hip Score and EuroQol 5-Dimension score showed that the daily step counts of patients who underwent bilateral or unilateral total hip arthroplasty without arthritis in the opposite joint significantly increased postoperatively, but that of patients who received unilateral THA with arthritis in the opposite joint did not change significantly. The Oxford Hip Score indicated an improvement in hip joint function after surgery, but the EuroQol 5-Dimension score did not show a significant change postoperatively in patients who received bilateral total hip arthroplasty.Conclusion: The pre- and postoperative comparisons of the participant’s daily step count after bilateral and unilateral operations without arthritis on the other side showed improvements in their amount of daily life activities. In all surgeries, Oxford Hip Score improvements were confirmed. The EuroQol 5-Dimension score of bilateral operations did not change. Bilateral operations and an understanding of unilateral postoperative qualitative support will be necessary in the future.