Ninety-seven percent of 81 patients had a transferrin saturation (TS) level >80% from day 0 of their stem cell transplant. This phenomenon was inversely related with reticulocyte count changes (p<0.0001). The time with a TS > 80% was predicted by reticulocyte recovery (p=0.031) in multivariate analysis. The kinetics of TS is a direct consequence of erythropoietic activity during stem cell transplantation.