The issue of controlling discretion in large public institutions is a crucial one in modern society, and procedural legal reforms are often viewed as one tactic of control. Using due process guarantees in juvenile courts as the substantive issue, this paper tests the utility of procedural reform in reducing discretion. Results indicate that procedural reform in the juvenile court has a quite limited impact. Few changes in the role of legal actors or in case outcomes result from the mandates in juvenile courts. Further, the results suggest that procedural guarantees may have minimal impact in other organizational contexts. Four mechanisms (Impact by definition, Impact by atmosphere, Impact by constraint, Impact by a change in Decision-Rules) may insure that compliance reduces discretion, and it is argued that procedural reforms can seldom successfully make use of these mechanisms. (Author)