Organizational research has shown that decision-makers can be subject to ethical blindness, a temporary inability to see the ethical dimension of a situation at hand. Previous theoretical approaches have identified organizational routines—recurring multi-actor practices—as important indirect context factors of ethical blindness. The present article argues that earlier theorizing is incomplete. Organizational routines may be a much more direct cause of ethical blindness and they may play a much stronger role in fostering unintentional unethical behavior than is currently acknowledged. As its main contribution, the article synthesizes research on unethical organizational behavior with findings on the micro-foundations of organizational routines to systematically theorize about when and how routines can directly cause ethical blindness. Given that organizational routines are not only a main pillar of organizational research but an indispensable part of organizational life, an increased understanding of their role in creating ethical blindness is of high theoretical and practical relevance. In particular, a routine-based explanation of ethical blindness may help in identifying and counteracting “everyday” unethical practices that are prevalent in modern business organizations.