Objective: To investigate the possible effects of preop-erative Neuromuscular Electrical Stimulation (NMES) to the quadriceps and hamstrings for the patients undergoing Total Knee Replacement (TKR) during the immediate postoperative period. Design: Prospective, randomised controlled study. Participants: 36 patients with osteoarthritis(OA) of the knee who were waiting for the elective TKR were randomly assigned to 1 of 2 groups (18 per group): control and study group. The study group patients received NMES to the quadriceps and hamstrings preoperatively. One patient in the control group and five patients in the study group were excluded due to the following reasons: operation postponed (two), unicompartmental knee replacement was performed (one), patients not willing to continue to use NMES due to personal reasons (two) and inappropriate/unable to use NMES (one). Both the control and the study group patients received standard physiotherapy postoperatively. Intervention: NMES (100Hz frequency; 0 to 55 volts amplitude; 1 second on/1 second off stimulation protocol) to the quadriceps and hamstrings muscle groups for 3 to 6 weeks preopera-tively. Amplitude adjustments and usage timings were made by patients (at home) as dictated by the comfort level. Main outcome measures: Immediate postoperative assessment of straight leg raise, stair walking, flexion of knee, pain, walking distance, length of stay for rehabilitation and total length of hospital stay. Limitations: Small number of participants and only early followups were performed. Results: The outcome data suggest a possible benefit, but did not reach statistical significance in all but one parameter, early stair walking.