Sports organizations face various ethical challenges. To tackle these, ethical codes are becoming increasingly popular instruments. However, a lot of questions remain concerning their effectiveness. There is a particular lack of knowledge when it comes to their form and content, and on the influence of these features on the effectiveness of these codes of ethics. Therefore, we developed a framework to analyze ethical codes and used this to assess codes of ethics in sports clubs from six disciplines (soccer, gymnastics, badminton, equestrian sports, tennis, and judo). The form and content characteristics of the codes were tested for their impact on the ethical climate of sports clubs. Our results show that most codes focus on the themes of integrity, and on solidarity among the members of sports clubs. Deontological phrasing is dominant in ethical codes in sports clubs. The occurrence of comprehension aids, such as examples, and procedural content, such as the mentioning of sanctions, is low. When it comes to code effectiveness, i.e., the influence on the ethical climate, we see a positive significant effect of the use of consequentialist oriented statements, and of the combination of regulatory and inspirational phrasing. Also the presence of explicit guidelines for the members of the board had a positive significant affect. This shows that codes should be a source of inspiration and stimulate moral awareness, rather than merely guide behavior by simple rules. Other content elements do not influence code effectiveness, suggesting that ethical codes merely have a function of raising ethical awareness in sports clubs. These results help to shed light on what it takes for a code of ethics to become a useful and effective instrument to tackle unethical behavior in sports clubs.