Shari’ah based banking have gained good momentum over a short period of time by expanding their activities on the lines of contemporary financial markets. Service quality and customer satisfaction are going to be key differentiators for each Islamic bank from their competitors. The purpose of this study was to evaluate the perception on service quality and level of customer satisfaction in Islamic banks particularly in Social Islami Bank Ltd.(SIBL). A survey was conducted conveniently on 100 retail banking customers in Dhaka city to collect primary data with the help of a structured questionnaire. The study has found that the customers’ perception about the service delivery system and products/services offered by the bank are at a satisfactory level except the product Bai-Salam and the ATM Services. Location of the branch gets the higher priority to the customers followed by employees and physical facilities of the branch among the service delivery system of the bank.