We estimated the proportion of the nation's public school districts that have high school grades in which random drug testing is conducted. We collected data in spring 2005 from 1343 drug prevention coordinators in a nationally representative sample of school districts with schools that have high school grades; of these districts, 14% conducted random drug testing. Almost all districts randomly tested athletes, and 65% randomly tested other students engaged in extracurricular activities; 28% randomly tested all students, exceeding the current sanction of the US Supreme Court.