The study sought to identify factors which were based in schools which affected the performance of sixth form students in science in Victorian schools, In order to identify school effects, allowance was made using multiple regression analysis for factors which were shown to contribute to academic performance but were those over which the school had no control. Use was made of information collected during a. study of science achievement by the International Association for the Evaluation of Educational Achievement (IEA). A sample of 37 schools was used the probability of selection of the school was proportional to its enrolment. Within each school, a random sample of students in the sixth form was made to select the students to take part in the testing program. Information collected enabled a predicted score for each school to be made and this was compared with the actual score obtained by averaging the scores of each student in the sample. Two groups of five schools were then selected for comparative study; one group which had performed better than expected and the other which had performed below expectations. The comparison of the two groups of schools to identify school factors was achieved by the study of the responses of teachers, students and school principals on survey instruments. In addition a visit was made to each school to gather further information. These procedures enabled the identification of school characteristics which were seen as contributing factors to the performance of students on tests of science achievement.