This study uses a specific method to analyze the contents of the codes of ethics of the largest corporations in Australia, Canada and Sweden and compares the findings of similar content analyses in 2002 and 2006. It tracks changes in code contents across the three nations over the 2002-2006 period. There were statistically significant changes in the codes of the three countries from 2002 to 2006: the Australian and Canadian codes becoming more prescriptive, intensifying the differences between these and the Swedish codes. The contents of these codes and the nature of the changes they have undergone over time are culturally driven: Australia's and Canada's reflecting their similar cultural profiles and Sweden's reflecting its differences from these countries on organizationally relevant cultural dimensions. The study reveals that corporate codes of ethics are living documents as reflected by the significant longitudinal changes in the frequencies of mention of several of the 60 items underpinning the content analysis of the codes of ethics. Consequently, and in light of their growing prevalence and importance as instruments of corporate governance, they should not be treated as static but as dynamic documents that are subject to various environmental factors. The clear implication of the findings of this study is that for corporate codes of ethics 'one size does not fit all' and that these instruments must be carefully monitored and revised to reflect changing conditions. © 2010 The Authors.