Based upon selection standards of size (serving a population in excess of 500,000 citizens or employment of more than 1,000 sworn personnel), geographical distribution, and comparability, 20 agencies were contacted by letter and asked to submit copies of policies, procedures, rules, collective bargaining agreements, civil service regulations, and any other written materials related to internal affairs investigations, the disciplinary system, and other matters not addressed in this paper. The factored variables for the qualitative analysis were grounds for discipline, the internal investigation, the adjudication process, disciplinary sanctions/alternatives, and disciplinary appeals. In presenting the findings, the author first describes the general literature and recommends practices associated with each variable. This is followed by an aggregate presentation of the findings from the content analysis. The study found that although variability existed on a number of procedural points, the departments showed a consensus of major trends in the disciplinary process. Perhaps the most significant factor that affected the structure of a police disciplinary system was the presence of a collective bargaining agreement with a police union. From a historical perspective, the most significant change in police disciplinary practices over the last 20 years has been the institutionalization of more explicit due process rights of personnel. 1 table, 4 notes, 9 references, and 5 study questions