As the Internet connections and services at U.S. public libraries have increased dramatically since 1990s, defining, assessing and measuring quality of these new electronic services have become a critical issue. This research was a study designed to identify key dimensions of Internet service quality at public libraries by providing a systematic framework for measuring and assessing the quality of Internet services. The study used modified SERVQUAL and SERVPERF instruments which have been widely used service quality measurement in business marketing areas and LibQUAL+ model which are widely adopted service quality measurement instrument in most of the academic libraries in U.S.