PURPOSE: Knee swelling after total knee arthroplasty may impair postoperative mobilisation and training, and as medical elastic compression stockings are well tolerated and effective to prevent oedema, haematoma and postoperative pain after venous surgery, we wanted to study whether this effect could be transferred to total knee arthroplasty surgery reducing postoperative swelling and pain and thereby facilitating mobilisation and improving patient-reported knee function. METHODS: In a randomised controlled study, 88 patients were randomised to use either a medical elastic compression stocking or no stocking from the first postoperative day and the following 4 weeks after total knee arthroplasty. Outcome measures were knee, calf and ankle swelling, knee flexion, pain and patient-reported knee function. RESULTS: Seventy per cent of the swelling had occurred before application of the stocking the day after surgery. Knee, calf and ankle swelling and knee flexion measured on days 2, 7, 14 and 30 showed no significant difference between the two groups. Maximum pain level at rest and at walking was similar for both groups during the observation period. Also, the Oxford knee score was similar between the two groups on days 14 and 30. CONCLUSION: We did not find any clinical effect using a medical elastic compression stocking after total knee arthroplasty. LEVEL OF EVIDENCE: I.