The sterilization of dental instruments is an area of great interest and recent concern in the field of dentistry. The purpose of this study was to compare the ability of three lasers (argon, CO2, and NdYAG) to sterilize dental instruments. Endodontic reamers were contaminated with microorganisms, lased at various levels of energy, placed in Trypticase soy broth, incubated, and read for growth or no growth to determine sterility. Results indicated that the argon laser is capable of sterilizing selected dental instruments at the lowest energy level (1 watt for 120 seconds) of the three lasers tested. The other two lasers were able to sterilize the instruments also, but at higher energy levels. Results indicated all three lasers capable of sterilizing selected dental instruments; however, the argon laser was able to do so consistently at the lowest energy level of 1 watt for 120 seconds.