Effective leadership by school principals requires the ability to plan, organize, motivate, control, anticipate, orient, coordinate, implement, staff, make decisions, and program, all effectively. These abilities can be exercised in different ways, however, and several different directions, purposes, and attitudes can be emphasized by the leader. These differences determine leadership style. Principals who understand their own leadership styles and who are able to fit their leadership styles to their particular situations (or their situations to their styles) are more likely to be effective leaders. Among the factors that must be considered are the extent to which human relationships are stressed, the extent to which technical tasks and their completion are stressed, and the extent to which the leader can diagnose the situation in which leadership must be exercised. When making such a diagnosis, the leader must assess the knowledge of those doing the work, their ability and willingness to accept responsibility, and the leader's own expertise in the work situation in question. This publication reviews the developing concepts of leadership style, provides examples of the appropriate use of styles, and notes the value of understanding and using the concepts presented. (PGD)