One hundred patients scheduled for a total knee arthroplasty were randomized to receive intra-operative iron isomaltoside (n=50) or placebo (n=50) for the prevention of post-operative anemia. The primary outcome of interest was the incidence of anemia at 30 days post-operation. Secondary outcomes of interest included hemoglobin (Hb) levels, iron panels, post-operative transfusion rate, length of stay, incidence of infection, and quality of life on the EuroQol 5 Dimensions (EQ-5D) questionnaire. Results of this study found a significantly lower rate of post-operative anemia in the iron isomaltoside group compared to placebo (p=0.008). No significant differences in post-operative transfusion rate, length of stay, surgical site infection rate, or quality of life were observed between groups (p>0.05 for all). Iron panel variables were significantly in favour of the iron isomaltoside group at 30 days post-operation (p<0.05 for all).