In this conceptual article, we look at the impact of culture on ethical decision making from a Douglasian Cultural Theory (CT) perspective. We aim to show how CT can be used to explain the diversity and dynamicity of ethical beliefs and behaviours found in every social system, be it a corporation, a nation or even an individual. We introduce CT in the context of ethical decision making and then use it to discuss examples of business ethics in the Indian business context. We argue that the use of CT allows for a theoretically more sophisticated treatment of culture in ethical decision making and thus the avoidance of some common problems with existing cross-cultural studies of business ethics. In our discussion, we raise questions about the compatibility between management systems and processes created in one context and ethical behaviours in another.