The ethical behavior of information systems personnel remains a key IS management problem in need of attention. Codes of ethics have become important mechanisms for influencing ethical behavior, yet their efficacy has not been proven. The communication and enforcement of codes within an organization are thought to be necessary for ensuring a code’s success in influencing employee behavior. This study examined the effect of code communication on ethical behavior through its effects on code awareness and understanding. Using data collected from 186 IS professionals, results revealed that code understanding by IS professionals was a significant determinant of their ethical behavior. Understanding was significantly influenced by communica- tion and awareness. Enforcement was also found have a significant influence on behavior. Results have important implications for organizations using or intending to use codes of ethics to influence the behavior of IS personnel.