Of all the complications that might occur while you are doing an endodontic procedure, one of the very worst is instrumentation breakage—in other words, “file separation” in the canal. Throughout my more than twenty years of practice, breaking an instrument in the canal has always been a major challenge for anyone doing endodontics. Recently, with the advent of rotary NiTi instruments, the manufacturers of these instruments seem to want us to believe that breakage is not such a problem anymore. Unfortunately, that is not the reality of the situation. Breakage is a problem, it remains a problem, and with the advent of NiTi instruments it is becoming an even larger problem. During any endodontic treatment there is a big possibility of fracture of endodontic instruments during the instrumentation phase of the treatment that might complicate the whole treatment later on. Some fractures can be removed from the canals with a great difficulty, other fractures cannot be removed from the canals which might compromise the final success of our treatment or complicate the treatment from simple endodontic treatment into periapical surgery than sometimes cannot be done because of close association with certain anatomical landmarks. Therefore, in this lecture, I will discuss the causes behind this mishap and the means by which we can prevent the fracture of endodontic instrument.