Although peer leaders have been effectively assisting school staffs since the 1960s, they have recently assumed their most critical role to date. Peer leaders are leading other students through drug prevention curricula, particularly those based on the Special Influence Model (SIM), which seeks to stregthen students' awareness of and resistance to external pressures exerted by family, friends, and the media, and to internal pressures such as low self-esteem that can lead youth to drug use. In addition, peer leaders are serving as prevention program administrators and often are taking the leadership in developing alternative drug-free school and community activities. (ABL)