This article describes the development of a new theory and measure of ethical work climate. Three studies are conducted to construct the Ethical Climate Index (ECI) and measure the ethical work climate dimensions of collective moral sensitivity (12 items), collective moral judgment (10 items), collective moral motivation (8 items), and collective moral character (6 items). Results of the third study indicate that the ECI is a reliable instrument and support the convergent and discriminant validity of each. Furthermore, results support the predictive validity of the ECI with respect to ethical and unethical behaviors.