This study tests the hypothesis that repeat steam sterilization will result in an increase in the rate of holmium:YAG laser fiber failure during bench testing in a series of commercially available single use and reusable small core sized (200-272 μm) holmium:YAG laser fibers. Single use and reusable small core-sized holmium laser fibers were tested. Single use fibers included the Dornier Lightguide Super 200, Dornier DUR Laser Fiber Single Use, Optical Integrity Scopesafe 272, IQinc. LLF200TG-D and LLF273TG-D, Boston Scientific AccuFlex 200 and AccuFlex 273, and Lumenis Slimline EZ 200. Reusable fibers included the Dornier DUR Laser Fiber Reusable, Lumenis Slimline 200, Sharplan 200, Laser Peripherals RBLF-200, IQinc. LFT273NT, and Convergent Optiview SMH1020F. A Lumenis VersaPulse 100 watt and a PowerSuite 20 watt holmium:YAG lasers were used. Fibers were bent to 180 degrees at a diameter of 1.5 cm. The laser was fired at 1.5J, 10Hz for 30 minutes or until fiber fracture. Reusable fibers were sterilized for a total of twenty cycles using the manufacturers' specifications and retested after every five completed cycles. No fiber fractured with bending alone. Two of three Dornier Super 200 single use fibers fractured repeatedly within several laser pulses. The Laser Peripherals RBLF-200 fiber fractured during initial but not repeat testing. One of three reusable Dornier DUR Laser Fibers failed during testing after the twentieth steam sterilization cycle. Five of five Boston Scientific Accuflex 200 failed at the SMA connector and did not couple well with the Lumenis Powersuite laser. The test hypothesis was not supported.