Healthcare assistants (HCAs) do not receive any mandatory training in ethical theory. This has the potential to result in poor ethical decision-making, and be an obstacle to understanding and appreciating the diversity of moral views between patients and colleagues. Here we explore the four most prominent ethical theories in healthcare ethics that inform peoples’ actions and beliefs (whether they are aware of it or not), from everyday moral decisions to more abstract ethical dilemmas: utilitarianism, deontology, virtue ethics and principlism. Although other approaches to ethics do exist, an introduction to these four will provide a good foundation from which to explore the topic further. Some HCAs may question if understanding ethical theory has any real world application for them and their practice. However, there are several good reasons for doing so. First, understanding ethical theory helps inform ethical decision-making. Second, it improves confidence and competence for making future ethical decisions. Third, it helps to understand how and why patients or colleagues may not share the same moral outlook. Fourth, it can increase an HCA’s ability to correctly identify moral problems and obstacles to good practice in the workplace. Ethical theory can be difficult to understand because it can appear abstract and irrelevant to everyday practice; but it need not be. An easy way to think of ethical theory is to see it simply as the attempt to identify and classify moral standards or rules that should, or do, guide our behaviour (Hendricks, 2004). Although there is a technical difference between the terms ‘ethical’ and ‘moral’, they will be used interchangeably throughout this article. Utilitarianism Utilitarianism is a widely adopted moral theory that is the best-known example of consequentialism, a class of moral theories that are solely concerned about the consequences of our actions—whether they bring about the desired results. In effect, the end justifies the means. The basic concept has been around for millennia: an example is in the New Testament (Holy Bible, New International Version, 1984), where the high priest, Caiaphas, advises the Jewish council to have Jesus killed, stating ‘it is better for you that one man die for the people than that the whole nation