This study investigated the effect of institutional size and complexity on professional autonomy in academic institutions. Autonomy was defined as the ability to set goals and to structure the organization to maximize professional concerns; size was measured by the number of faculty members and students in the institutions. Data were gathered from 241 colleges and universities in the United States, and from more than 9,200 individual faculty members and administrators using a questionnaire. Responses to the questionnaire were examined with regard to patterns of decisionmaking, departmental control over faculty selection, courses, tenure, and budgets; and peer evaluation. The data showed a strong trend toward greater faculty autonomy in larger institutions. It is hypothesized that this was so because the larger institutions had more complex tasks and were divided into more specialized units composed of more highly trained experts whose expertise gave them power to demand the autonomy they desired. The larger schools had less centralization of decisionmaking, fewer bureaucratic regulations covering professional tasks, more departmental and individual autonomy, more evaluation by peers, and greater protection from outside demands. A 10-item bibliography is included. (Author)