abstract This paper is an investigation of the moral psychology of decisions that involve a conflict of interest. It draws on the burgeoning field of affective neuroscience, which is the study of the neurobiology of emotional systems in the brain. I show that a recent neurocomputational model of how the brain integrates cognitive and affective information in decision-making can help to answer some important descriptive and normative questions about the moral psychology of conflicts of interest. These questions include: Why are decisions that involve conflicts of interest so common? Why are people so often unaware that they are acting immorally as the result of conflicts of interest? What is the relation of conflicts of interest to other kinds of irrationality, especially self-deception and weakness of will? What psychological, social, and logical steps can be taken to reduce the occurrence of immoral decisions resulting from conflicts of interest? I discuss five strategies for dealing with conflicts of interest: avoidance, optimal reasoning patterns, disclosure, social oversight, and understanding of neuropsychological processes.