Objective To assess the effects of suction drainage versus nondrainage on the post-operative rehabilitation of patients receiving primary bilateral total knee arthroplasties (TKA). Methods A prospective study including 40 patients was conducted. These patients were diagnosed with osteoarthritis and underwent primary bilateral TKA between October 2007 and September 2009 with the same operation team. A suction drainage was placed by randomization in only one knee for each patient, while the other knee as self-control. Pain visual analogue scale score, extremity swelling, wound healing, range of motion and incidence of early post-operative complications between the drained and nondrained group were compared statistically. Results Each patient was followed up for 12 months. Placing drainage did not relieve the pain, extremity swelling, ecchymosis, or reduce the incidence of early complications (all P>0.05). Conclusions Suction drainage in TKA does not exhibit substantial advantages in promoting post-operative rehabilitation after unsophisticated TKA, compared with nondrainage. On the other hand, it might complicate the surgical operation, and increase the incidence of post-operative hemorrhage and retrograde infection.Thus we do not recommend suction drainage in unsophisticatedTKA.