The benefits and risks of Simultaneous Bilateral Total Knee Replacement (SBTKR) remain controversial. A review of the English speaking literature was undertaken and found that many papers took staunch positions either for or against the procedure. It was also noted that earlier papers supporting SBTKR suggested cost benefits. There was a huge disparity in the incidence of mortality and morbidity and it was not possible to compare many papers, because in some medically frail patients were excluded from the SBTKR cohorts. In large published series the proportion of patients having a SBTKR varied between 3% and 70%. Many, but not all, series highlighted age and co-morbidity as risk factors. Overall there was no clear case for or against SBTKR. The evidence suggested that careful preoperative assessment and patient selection on a strict protocol were essential. The procedure should be confined to hospitals where high dependency nursing is readily available and the literature indicated that the risk is less in high through-put units. By refining preoperative assessment and preparation it can be a safe and effective procedure in an appropriate clinical setting for postoperative care.