Objective To study the outcomes of 2 rehabilitation protocols after simultaneous stage Ⅰ bilateral total knee replacement (TKR). Methods One hundred and twenty patients admitted for stage Ⅰ bilateral TKR were assigned randomly to receive alternative or traditional rehabilitation therapy. Rehabilitation training was administered in both alternative and traditional groups before and after operation. In alternative group, each rehabilitation action was designed to be done on one side and the other side alternatively. In traditional group, each training session was designed to be done on one side and then followed by the other side in succession. Visual analogue scale (VAS)scores were evaluated for 2 weeks after operation and deep vein thrombosis (DVT) complications were recorded for 3 months after operation. The range of motion ( ROM), American hospital special surgery (HSS) knee scores and SF-12 scores were recorded at 1 d before operation and the 1st, 3rd, 6th and 12th month after operation, Results One hundred and fifteen patients completed all training sessions and assessments. Compared with traditional group, alter-native group had significantly lower VAS scores in the early postoperation stage and significantly better knee function scores and SF-12 scores at the 1 st and 3rd month postoperation (P <0. 005). Conclusion The alternative protocol can speed up rehabilitation and lead to decrease VAS scores in the early postoperation stage, and improve knee func-tion and physical and mental health after TKR.