A considerable amount of academic attention has been directed towards the relationship between service quality and customer satisfaction. But the nature of the exact relationship is still shrouded with uncertainty. In addition, few researches focus on the dimensions of service quality and their differing impacts on customer satisfaction in western fast food restaurants. This paper examines whether or not quality and satisfaction should be considered as a single construct, or distinct, separable constructs. Customer satisfaction is typically evaluated by means of a single item scale and sometimes multiple item scales. Conversely, this empirical study adopts a different approach and considers customer satisfaction as a multi-dimensional construct just as service quality, but argues that customer satisfaction should be operationalized along the same corresponding items on which service quality is operationalized. The SERVQUAL instrument was slightly modified to measure the relationship between service quality and customer satisfaction among customers in western fast food chains in Kaohsiung. The research survey captures customers¡¦ perceptions of excellent service and compares it with their overall satisfaction. Using multiple regression analysis and T-test, the paper also reports on how socioeconomic and demographic disparities can influence the perception of service quality and satisfaction. Based on the research findings, the service quality and customer satisfaction are indeed independent but are closely related constructs. Their relationship suggests that an increase in one will lead to an increase in another. The statistical analysis also revealed that demographic variables can have major influences on service quality and customer satisfaction. The aim of the study is to supply useful results for future customer satisfaction researches in the fast food industry and provide insights into market segmentation strategies.