This study examined the relationship of school ethical climate and students' school performance within the context of a Chinese high school. Gender and grade-level differences in ethical climate perceptions were also explored. Survey data on perceptions of school ethical climate based upon the dimensions of student-to-teacher, student-to-student and teacher-to-student interactions and relationships were obtained from 754 students. Results of the study showed that students' perceptions of their high school's ethical climate were related to academic achievement, gender and grade level. Students' involvement in extracurricular activities and student leadership generally did not seem to relate to their perceptions of ethical climate. Based upon these findings, the school's moral education intervention programs should increase their focus on the area of teacher-to-student relationships and interactions and the subgroups of male students, students in higher grades and students with lower academic achievement. Implications for future research on school climate are also discussed. (Contains 4 tables.)