Abstract A battery of tests was administered to three trial groups who studied the Israel BSCS Adaptation Program for several years. Compared with non-BSCS students the performance and progress of the BSCS students in three cognitive areas, namely biological knowledge, inquiry skills and the understanding of science, demonstrates the feasibility of the BSCS adaptation program for students in academic city schools as well as for those in the Kibbutz rural schools. It is less adequate for most students in agricultural schools as well as for a considerable number of students of non-European descent. The results indicate that achievement in biology is not unidimensional and that different students reach different levels of achievement with different measures. The implications of the findings regarding program revision, teacher training, adoption as well as further research are discussed. The study may be helpful to other countries which either have adapted or considered the adaptation of programs such as the BSCS.