This paper describes the philosophy, implementation, and assessment of the Natural Sciences (NatSci) Program at the University of New Mexico which is designed to provide preservice elementary and middle school teachers with the understanding of science content and processes necessary to teach science confidently and competently in their future classrooms. The program's emphasis on small classes, concept-building, integration of sciences, diverse learning styles, and the use of constructivist teaching techniques appear to be successful in increasing students' comfort level in science. (WRM)