A ten-item questionnaire containing various descriptions of school-related characteristic which have been found to adversely affect pupils academic performance was administered on 809 teachers and 1012 students of secondary schools from ten randomly selected states in Nigeria. The respondents ranked the characteristics in terms of their degree of effect on pupil academic performance. The result showed that lack of resource materials for teaching, instructional strategies, teacher shortages and teachers' attitude to work were rated more highly than other characteristics. The result further showed that while the teachers considered lack of resource materials for teaching as having the greatest degree of effect on pupils academic performance, the students on the other hand considered poor instructional strategies as having the greatest degree of effect on pupil academic performance.