Existing literature has revealed that the demand for "ethical products" has been increasing over time. However, very little has been published on consumer perception about the ethical behavior of supermarkets and their response thereto. This research, therefore, fills the vacuum. We examine consumer perception about the ethical business of supermarkets operating in the UK and its impact on consumers' supermarket choice. Both primary and secondary data are used; primary data includes a questionnaire survey involving 222 consumers in major cities in the UK. We examine the significant code of business ethics, consumer ethical spending and awareness, supermarkets’ ethical performance and popularity, and consumer perception about supermarkets’ ethical behavior and their response thereto. A combination of graphical and numerical methods, such as frequency distribution, correlation and analysis of variance, has been used for estimation. Estimated results confirm the significant code of ethics in the supermarket business as perceived by consumers. Specifically, environmental awareness, fair trade, concern about labor law and animal welfare are found to be a significant code of ethics in the retail business. However, in practice, supermarkets are selected based on whether they maintain organic produce, fair trade, and animal welfare. The results suggest that there is a significant "knowledge gap" between actual ethical business practice and consumers' perception about it. There is also a significant "behavioral gap" between consumer perception about ethical business and their response to it. Demographic variables make a significant distinction in ethical business choice. Education, income, and ethnicity play a significant role in ethical supermarket selection.