Sixty patients were operated on for primary gonarthrosis by means of a cemented, posterior cruciate preserving total knee and were randomly allocated to postoperative drainage or nondrainage. The primary criterion was duration of hospital stay. Secondary criteria included serial evaluation of knee pain, knee flexion, knee circumference, calculated blood loss after 7 days, complications, reoperations, and the need for blood transfusions. There was no difference between the two groups in any of the criteria during the entire follow-up. There was a nonsignificant trend to a decreased calculated blood loss in the nondrained group and significantly less transfused blood units in the nondrained group. Lack of drainage does not increase complication risk after total knee prosthesis implantation. We therefore recommend using no routine drainage after this procedure.