The specific objectives of the study are to analyze customer's perception, expectations, and their gap and suggest appropriate measures to improve the retail service quality at Spencer's hypermarket. The primary data was collected using structured questionnaire through personal interview method during February and March 2012 and were analyzed using percentage analysis, Garret ranking, factor analysis and gap analysis. General profile of the respondents revealed that majority of Spencer's customers were young aged, belonged to a medium sized family, well educated and mostly worked in private sector with an average monthly income of Rs. 20,001-30,000. The store activities reached consumers mostly through newspaper ads.78 percent of respondents preferred Spencer's among other supermarkets and live bakery was mostly preferred Spencer's category. Gap analysis of RSQS showed physical aspects and reliability were satisfactory dimensions while policy dimension was below satisfaction level. Therefore the retail store needs to make improvements in all dimensions in order to close the gaps that could lead to increasing customer satisfaction and gaining more loyal customers to the store.