The rapid expansion of university education in Kenya created pressure on quality of service delivery in the Universities. Customer focus, conducive working environment and continual improvement in performance were delimiting quality principles challenging delivery of satisfactory services to the University customers. There were fears that quality of education is on a downward trend in most universities and therefore Quality Management Systems was introduced in the Universities in 2004 to improve service delivery. Although studies have been done on the performance of ISO certification in universities, few studies have assessed the effect of Quality Management Systems (QMS) on service delivery in the Universities. The broad objective of the study was to assess the effect of QMS on services delivery at Jaramogi Oginga Odinga University of Science and Technology (JOOUST). The three specific objectives were to determine the effect of customer focus, work environment enhancements and continual improvement on service delivery at JOOUST. The study tested hypothesis on the significance relationship between QMS and service delivery. The study theory was Total Quality Management (TQM) and the design was a case study. The study population was N = 7,752 and a target population of 2,121. A sample of n = 326 was selected from the University students, suppliers and staff. Multi-stage sampling was used to determine the study sample. The dependent variable was the quality of service delivery and the independent variables were customer focus, work environment enhancement and continual improvement. Primary data was collected by use of semi-structured questionnaires, interview and observation schedules. Secondary data was obtained from document analysis guide. Statistical Package for Social Sciences (SPSS) was used in data analysis and Correlation analysis to determine the relationship between the variables. Regression analysis was applied to assess the effect of each explanatory variable on the response variable. The findings of the study show QMS significantly affect quality of service delivery at JOOUST. The study concluded that QMS has positively influenced service delivery at the University however satisfaction with service delivery has not improved much. The study recommends that JOOUST should strive to meet all QMS requirements and provide adequate basic resources needed by customers in order to enhance quality of service delivery in the University. The results of the study should be shared with JOOUST management and other university policy makers to assist in improving performance of QMS and enhancing the quality of service delivery in the Universities.