This study uses macrostructural theory, contact theory, and group threat theory to examine how schools influence interracial friendliness and interracial conflict. Using perceived measures of both interracial friendliness and interracial conflict with data from the High School Effects Study, results from multilevel models show partial support for all three theories. As predicted by macrostructural theory, school integration raises perceptions of both friendliness and conflict, with conflict increasing more rapidly. Consistent with contact theory, segregated tracks, fewer minority teachers, less group work, and segregated extracurricular activities worsen racial relations. In support of group threat theory, evidence suggests that students are especially likely to avoid interracial contact in biracial schools with equally-sized groups. These results emphasize the importance of researching both negative and positive outcomes simultaneously when studying racial relations. The research also alerts school personnel that integration will likely result in more conflict than friendliness unless proactive steps are taken.