With increased emphasis on state standards and assessments in science, one might question whether there is still a role for national science standards and benchmarks. This article makes a case for the importance of national guidelines and identifies key functions performed by the National Research Council's "National Science Education Standards" and the American Association for the Advancement of Science's "Benchmarks for Science Literacy." We describe how national guidelines provide a vision of what science education could be and its value to all students; consider the implications of aligning curriculum, instruction, and assessment to these guidelines; discuss the quality of current state standards; and consider what the national reform efforts have to offer states and school districts seeking to improve teaching and learning in K-8 science. (Contains 2 figures.)