Increasing competition in the grocery retail sector in Malaysia has moved many retailers regardless of size, to find competitive edges that could place them ahead of the rest. The prominence of foreign based retailers that are predominantly large in size is worrying the small and medium sized retailers. Yet, their attraction toward different types of grocery retailers may differ as Malaysian consumers become more discerning in their choices of retailers. This study explores the needs of customers frequenting retail outlets of different sizes and evaluates the service quality dimensions which should be given priority by retailers wishing to establish firm competitive edge. Results reported are exploratory and based on interview results. Findings suggest the existence of all dimensions from findings of Retail Service Quality Scale (RSQS) by Dabholkar, Rentz, and Thorpe, 1996. However, specific issues related with physical aspects and personal interaction differs for different sizes of grocery stores. This study also highlight the existence of halal as a critical dimension for grocery shopping in Malaysia .