AbstractLike any other asset, water pipelines deteriorate over time and become vulnerable to sudden failures, which often result in costly replacement actions. In recent years, various techniques have been developed for effective condition assessment of such pipelines. However, limited guidelines are available for selecting these technologies. The objective of this study was to fill the knowledge gap in the selection of inspection and monitoring technologies for large-diameter steel pipes (SP) and prestressed concrete cylinder pipes (PCCP) by developing a decision-support tool using analytical hierarchy process (AHP). A comprehensive condition assessment index (CAI) was developed for various inspection techniques by describing available inspection techniques, analyzing various failure modes and their causes, and developing a computer program that can select an appropriate inspection technique based on the factors that influence failures. The developed CAI is analyzed for each inspection method and a suitable technique is recommended based on impacting factors of individual pipes. This paper will help utility owners and agencies in making informed decisions regarding the selection of appropriate inspection techniques for large-diameter steel and prestressed concrete cylinder water transmission pipelines. Further studies are needed to better analyze the failure mechanism of large-diameter water mains to include prefailure indicators while estimating the CAI.