INTRODUCTION: During spaceflight, it is important to consider the mechanisms by which surgeries and medical procedures can be safely and efficiently conducted. Instruments used to carry out these processes need to be sterilized. Thus, we have designed and tested a three-dimensional-printed (3D-printed) portable sterilizer that implements far ultraviolet-C (Far UV-C) light radiation to disinfect bacteria and microorganisms from surgical instruments.METHODS: The sterilizer was 3D-printed with polylactic acid filament. Effectiveness was assessed through three trials at differing times of sterilization and compared against a control group of no sterilization and against Clorox wipes. Cultures were incubated on agar dishes and counted with ImageJ.RESULTS: Increasing time under Far UV-C light radiation increased the percentage of sterilization up to 100% at 10 min. The 3D-printed sterilizer was significantly better than Clorox wipes and control.DISCUSSION: As sterilization will be necessary for surgical procedures in microgravity and upmass is a significant concern, we have successfully demonstrated a 3D-printable portable sterilizer for surgical instruments that achieves 100% success in using Far UV-C light to disinfect its surface of bacteria with a 10-min sterilizing time. Further research is necessary to test this design in microgravity and with differently sized and shaped instruments.Kovalski E, Salazar L, Levin D, Kamine TH. A 3D-printed portable sterilizer to be used during surgical procedures in spaceflight. Aerosp Med Hum Perform. 2023; 94(11):857-860.