Pipeline infrastructures normally represents high cost of investment and the pipeline must be free from risks that could cause environmental hazard and potential threats to personnel safety, pipeline integrity such monitoring and management become very crucial to provide unimpeded transportation and avoiding unnecessary production deferment. Thus proper inspection is the key to safe and reliable pipeline operation and plays an important role in pipeline integrity management program and has become a standard industry procedure. In view of this basis, development and innovation of ILI tools are being viewed as paramount necessity by the petroleum industries. The objective of this paper is to review and distinguish possibly all types of existing ILI tools. It is hoped that the review would serve as an industrial application in a form of quick reference in identifying currently available ILI tools for pipeline inspection purposes. © 2011 IEEE.