This study assesses the effects of three aspects of school organization--student enrollment, student-teacher ratio, and the number of different students taught--on the property and personal victimization experiences of students. It hypothesizes that smaller schools, schools with lower ratios of students to adults, and schools in which the number of different students taught by the typical teacher is lower will produce less victimization because of the increased social capital to which students in these schools are exposed. Using data from the National Study of Delinquency Prevention in Schools, the authors find that, net of individual-level risk factors and confounding characteristics of schools and their surrounding communities, each of the three aspects of school organization is related to student victimization but that these effects vary across victimization type. Their research suggests that reducing the ratio of students to teachers and reducing the number of different students taught by the average teacher are likely to reduce student victimization. Reducing school size is not. The authors also find evidence that higher levels of social capital, as measured by student consensus about normative beliefs, partially mediate the effects of student-teacher ratio on personal victimization. (Contains 13 notes and 3 tables.)