Development of a scientifically literate citizenry has become a national focus and highlights the need for K-12 students to develop a solid foundation of scientific reasoning abilities and an understanding of nature of science, along with appropriate content knowledge. This implies that teachers must also be competent in these areas; but assessment of students in our teacher preparation program indicated they were not developing necessary scientific reasoning abilities or a sophisticated understanding of nature of science. As a result, explicit scientific reasoning-oriented training modules and reflective nature of science activities were integrated into the program's science foundations course. Significant gains were observed in each. These findings highlight the need and motivation for teacher preparation programs to incorporate coursework that promotes the development of scientific reasoning and a more contemporary view of the nature of science. In addition, this study provides a framework for the modification of existing teacher preparation courses to meet these needs. (Contains 4 tables.)