The focus of women in science constitutes an important component of the US National Science Foundation’s (NSF) strategic investment portfolio. The mission of the NSF is to promote progress across all fields of basic science and engineering through its investment portfolio in research and education. A high priority within that portfolio is broadening participation in science, technology, engineering and mathematics (hereafter, S&E). Some of the many NSF programs supported to broaden participation in S&E focus on women. The reasons for such investments include the benefits derived from the intellectual diversity in perspective brought to bear on the scientific enterprise and the progressive decline in women’s participation at advanced levels of S&E, especially relative to their representation in the general US population as well as their greater representation at earlier levels of the educational and career pathway. A few data reveal this latter point.