When a patient visits the Emergency Department (ED), the reason the patient is seeking care is recorded as the Chief Complaint (CC). Beyond its role in the patient’s care, there is interest in the CC for secondary uses. Clinicians and epidemiologists can use CC for research. ED clinicians and administrators incorporate CC data into quality monitoring and improvement efforts. Public health officials can use it as data for health surveillance. But there is no controlled vocabulary for recording CC, or standard for a CC component in the patient record. Travers (2003) completed a crucial first step toward the creation of a thesaurus for CC by analyzing a corpus of CCs to determine the nature of the language used by triage nurses, and the concepts that were expressed. Her analysis also illuminated many issues concerning the content and structure of a CC thesaurus that must be discussed before the thesaurus can be developed. Using Cimino’s 1998 article, “Desiderata for Controlled Medical Vocabularies in the Twenty-First Century”, as a framework, we discuss these issues and the resulting decisions that the thesaurus development team, along with other stakeholders, will encounter.