One hundred years ago, Flexner emphasized the importance of science in medicine and medical education. Over the subsequent years, science education in the premedical and medical curricula has changed little, in spite of the vast changes in the biomedical sciences. The National Research Council, in their report Bio 2010, noted that the premedical curriculum caused many students to lose interest in medicine and in the biological sciences in general. Many medical students and physicians have come to view the premedical curriculum as of limited relevance to medicine and designed more as a screening mechanism for medical school admission. To address this, the Association of American Medical Colleges and the Howard Hughes Medical Institute formed a committee to evaluate the premedical and medical school science curricula. The committee made a number of recommendations that are summarized in this essay. Most important were that competencies replace course requirements and that the physical sciences and mathematics be better integrated with the biological sciences and medicine. The goal is that all physicians possess a strong scientific knowledge base and come to appreciate the importance of this to the practice of medicine. While science education needs to evolve, Flexner's vision is as relevant today as it was 100 years ago.