This study seeks to expand our understanding of judicial deference to administrative agencies within the context of one particularly important legal forum – the U.S. Court of Appeals for the District of Columbia. The DC circuit functions as a key venue for administrative law cases and the opinions of the court constitute a growing body of common law in the field of administrative law. We investigate the importance of several agency-centered and judge-centered variables in explaining judicial deference to administrative agencies in cases before the DC circuit court during a twelve-year period (1985–1996). We find that an integrated model of judicial deference, combining both legal and attitudinal factors, best explains judicial deference. Like judges on so many other courts, judges on the DC circuit are politically motivated, but their political activism is tempered by agency-centered factors such as the type of case before the court, and environmental factors such as the composition of the judicial panel reviewing the case and the behavior of the Supreme Court.