I was recently asked about the biggest ethical mistakes CEOs make. In 35 years as an ethics consultant, I have seen some doozies. After all, you only hire an ethics consultant if you face an ethical dilemma. And once an ethical mistake occurs, it is extremely hard to set things right with the public and media, who already may believe that companies routinely engage in unethical conduct. The truth is that most of these mistakes are entirely avoidable—if you are on the lookout for them. Here are the top 5 ethical mistakes I've seen made by CEOs.