This multi-center, single-blinded, randomized controlled study assessed the efficacy of phased exercise rehabilitation programs in patients who underwent a total knee arthroplasty (TKA) and investigated suitable exercise types, intensities, and frequencies for patients undergoing postoperative rehabilitation. Between January and March 2018, 494 patients who had undergone TKA were treated at two medical centers. Patients were randomized and allocated to the rehabilitation group (n=330) or the control group (n=164; treated with postoperative care). The 100-mm Visual Analogue Scale (VAS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), range of motion, and Short-Form 36 (SF-36) scores were assessed and compared between the two groups. The average WOMAC score was 84.40±15.20 in the rehabilitation group and 108.30±3.90 in the control group (p=0.009). The mean VAS score was 2.54±0.16 in the rehabilitation group and 2.87±0.31 in the control group (p=0.024). Furthermore, the range of motion was 125.02±6.20 in the rehabilitation group and 116.40±1.40 in the control group (p=0.017). The mean SF-36 score was 105.40±21.50 in the rehabilitation group and 83.70±5.01 in the control group (p=0.043). This study suggests that the phase rehabilitation program could be more effective at improving pain, knee function, and quality of life than condition postoperative care after TKA.