The expanding complexities of American society and the demands placed upon educating American youth are causing the trainers of teachers to give increasing attention to developing innovative methods for improving teacher education. Since there is a lack of information concerning cognitive processes in the classroom and the effects of cognitive instruction with pre-service students in teacher education programs, this study concerned itself with these issues. Stated in the null form the hypotheses tested in this investigation were: (1) There will be no difference between the observed cognitive behavior of student teachers trained in cognitive instruction and those not so trained; and, (2) There will be no difference between the observed cognitive behavior of the pupils of student teachers trained in cognitive instruction and the pupils of those student teachers not so trained. A total of thirty-three subjects, an experimental group of seventeen and a control group of sixteen, were randomly drawn from a stratified sample and controlled on age, sex, and grade point average. Cognitive instruction was provided for the experimental group. Both hypotheses were rejected at the .001 level of significance. It seems appropriate to conclude that cognitive instruction can increase cognitive behavior in the classroom. (Author/SLD)