Sustainable service quality (SUSSERV) is crucial to identify how far the company able to meet customer expectations will determine its sustainability. SUSSERV model with six independent variables namely tangibles, reliability, responsiveness, assurance, empathy, and sustainability has been developed by modifying the SERVQUAL instrument. This research employed a survey with quota sampling technique through 500 questionnaires comprised of 250 each to the customers of water (WC) and sewerage (SC) companies in the state of Selangor, Federal Territory (FT) Putrajaya and FT Kuala Lumpur. The study found the respondents dissatisfied towards services rendered by both companies. WC's perceived service quality for all SUSSERV dimensions much lower than SC. There were no significant differences between the mean of perceptions except 8 from 31 variables and 3 from 31 variables each in the category of services and living status respectively. The importance-performance analysis indicated the Assurance and Responsiveness dimensions were at high levels but Sustainability dimension was low for both performance (perceptions) and importance (expectations). The findings not necessarily generalizable to other company in other states of Malaysia. Future research should focus on using this instrument in other states to further validate and test this instrument.