The departmental characteristics associated with the average duration of doctoral study were studied in a national data set collected by the National Research Council. The biological, mathematical and physical sciences, and engineering had relatively short medians and narrow ranges across departments, and the humanities had larger medians and wider ranges. The pattern of results associated with the duration of doctoral study suggested the importance of departmental emphases on scholarly careers and the resources to implement those emphases. The patterns of results varied by general area, and by specific discipline, suggesting the need for detailed analysis within disciplines.