Endodontic rotary files have been developed to improve the quality of root canal preparation. However, such instruments have a risk of separation. In most cases, the files are not checked for quality before use. Instead, they are often removed from the packages, sterilized and used without being examined for the presence of imperfections or debris. Practitioners were always to be blamed of such mishaps, but recently there has been some investigations claiming that these files are not flawless and far from perfection. A sample of 50 files from 5 companies were analyzed under scanning electron microscope (SEM) with 100× magnification and given to 3 blinded endodontic observers to investigate the presence of manufacturing defects. The products of these companies were: Protaper, K3fx, Easy Race, Wave One and Twisted File. All files from each company presented all the 6 categories of defects. Each file presented at least two types of defects. Significant variation was found between companies and defects (p value = 0.03). This study showed that all the brands that had been examined had manufacturing defects in addition to imperfection in packing conditions; however, the electropolished instruments had significantly less imperfection, particularly in term of grooves and scratches.