This study aims to evaluate the effectiveness and safety of the patients receiving simultaneous bilateral TKA (BTKA). A total of 93 consecutive patients with bilateral knee degenerative osteoarthritis from January 2008 to November 2013 were divided into two groups--one-stage group (bilateral TKA under a single anesthetic, n = 54) and two-stage group (bilateral TKA performed during two separate admissions, n = 39). The patients in the both group have a similar incidence of postoperative complications (p = 0.544). The one-stage BTKA can significantly (p < 0.05) decrease the operative time, length of stay, and hospital charges, when compared to two-stage BTKA. The patients in one-stage group have a significantly (p < 0.05) higher postoperative drainage, amount of hidden blood loss, amount of blood loss, allogeneic transfusion and rate of blood transfusion, compared with those in two-stage group. Patients in both groups had a similar KSS (p = 0.839) and ROM (p = 0.383). The findings suggests that one-stage BTKA may be safely performed with similar knee function to those of two-stage procedure, and has the added benefit of single anaesthetic, reduced costs and decreased hospital stay when compared to two-stage BTKA.