Although some safe schools analysts assume a link between climate and school violence and disorder, there has been little empirical data to support this assumption. Using survey data from 20 Florida middle and high schools, this research explored relationships between a school's climate and students' perceptions about the safety of their school environments. Climate was measured by students' perceptions of the following: fairness of discipline, consistency of discipline enforcement, teacher control over classroom disruption, fairness of grading, teachers' willingness to assist with schoolwork problems and whether teachers cared about students. Controlling for student demographics, attitudes and behaviors as well as for unique school characteristics, school climate was found to be a key determinant of students' perceptions about safety. Students were more likely to report feeling safe and less likely to report serious classroom incidents in schools where teachers were perceived as having control over classroom misbehavior and discipline was seen as consistent and fair. In addition, students were more likely to report feeling safe in schools where teachers were seen as caring and helpful with schoolwork problems. Students were also less likely to report serious classroom incidents in schools where grading was seen as fair. These positive climate factors were not only key factors in making schools safer, they were better predictors of serious classroom incidents and feeling safe than were student qualities or other school factors. Climate factors were also better predictors of student reports of feeling safe than serious incidents or other school qualities. Even in schools with a higher frequency of serious classroom incidents or higher proportions of disadvantaged students, students were more likely to report feeling safe in schools with positive climate factors. Challenging a major assumption of safe schools programs, these results suggest that simply focusing on reducing the frequency of serious classroom incidents will not guarantee that students will feel safe. Rather, findings indicate that positive climate factors need to be an integral part of any program for developing a “safe” school. Finally, the results suggest that educators can reduce the likelihood of aggressive incidents in classrooms by improving the school's climate.