Teacher beliefs and environmental conditions influence student performance outcomes. In this nonequivalent comparison quasi-experimental design study, students enrolled in ten secondary Principles of Agriculture courses assigned to a control or treatment group based upon their sexual identity. Teachers were asked periodically about their expectations of student performances. Over the course of the academic semester, students within the treatment group maintained higher grade point averages and better attendance. Boys from the treatment group maintained a higher percent of non-discipline referrals than boys from the control group. In addition, correlations are made between the teachers' expectations, and student performance and career aspirations. The researchers recommend that secondary schools consider single-sex classrooms for entry-level agricultural courses and for additional research to be considered to further strengthen the preliminary findings.