To identify fall risks in patients undergoing hematopoietic stem cell transplantation (HSCT), the authors reviewed retrospective data on inpatients from April 2010 to March 2011. Among 77 HSCT patient records reviewed, the authors found that 35 patients had experienced at least one fall, including near-miss episodes (fallers). The main location of the falls was a corridor, and the main activity at the time of the fall was going to the toilet. To investigate fall risks along the HSCT time trajectory, the authors divided the time into pre- and postengraftment periods and investigated the unique characteristics of each.