Purpose: The purpose of this paper is to examine selection factors among multi-ethnic customers in Malaysian Islamic banking industry. The information is important to reinforce the argument that ethnicity could become significant factor in determining customer behaviour. Design/methodology/approach: This study uses quantitative approach by using questionnaire (Likert scale) to measure respondents ranking of 25 selection factors. A total of 272 valid responses were generated from 450 questionnaires distributed, with 60.4% response rate. The methods of analysis used are descriptive analysis, factor analysis and Kruskal–Wallis test. Findings: The findings revealed five selection factors (religious and ethical, services and convenience, service quality and benefit, external and operational and charges), with religious and ethical factor as the most important criteria for Malay customers. As for Chinese and Indian customers, they chose services and convenience factor. Originality/value: This study is conducted to gain new insights on the perception of multi-ethnic banking customers in Malaysia towards Islamic banks and how cultural differences might affect their decisions. The findings are important for further development of the Islamic banking industry in Malaysia considering ethnicity has a major impact on the society. The acknowledgement of similarities and differences between the ethnic groups could strengthen the relationship with the Islamic banking customers. Furthermore, incorporation of ethnicity factor in bank’s marketing strategies is important to secure competitive advantage particularly in dual banking system such as in Malaysia.