After a scientific and professional association has developed a code of ethics, it must develop a set of procedures to investigate, adjudicate, and enforce the code's provisions. The author, who is a scientist and an attorney, describes and discusses the fundamental legal principles that must be adhered to so that complaints against members can be adjudicated fairly, objectively, and with little legal risk to the association. The paper defines the concept of due process as it applies to private, non-profit associations and provides an example of how one professional and scientific association actually goes about adjudicating claims of misconduct against its members. It also informs associations about the liability risks that may confront them when they enforce a code of ethics, offers suggestions of how to manage those risks successfully, and concludes by cataloguing some of the financial burdens enforcement entails.