The aim of the study was to analyze the influence of supplier debarment on service delivery of water companies in Murang’a County. The agency theory served as the foundation for this study. The employed a descriptive research design. The target population for the study included 240 employees from the five water companies in Murang’a County. Purposive sampling was used as the study focused on the procurement department, heads of user departments, and customers. A sample size of 150 respondents were selected for the study. Questionnaires were used by the researcher to collect primary data. By use of SPSS software version 21, quantitative data was analyzed using descriptive statistics and reported as percentages, means, standard deviations, and frequencies. Findings indicate R Square of 0.825 which implies that 82.5% of water companies' service delivery can be attributed to the debarment of suppliers. It was concluded that debarment of suppliers’ boosts service delivery of water companies. The study recommends that organizations should enact debarment policies to provide a potentially significant mechanism in the fight against corruption by barring bidders who have committed "corporate integrity offences" from procurement contracts. It is further recommended that organizations that experience nonperforming suppliers should institute debarment by PPRA instead secretly debarring suppliers which results to the same non-performing suppliers being awarded contracts by others firms whereby such firms fails to perform again.