This paper examines the level and determinants of students’ plans to major in engineering when entering college. (1) How has the gender gap in incoming college students’ intent to major in engineering changed over the past 4 decades? (2) What are the determinants of women’s and men’s decision to major in engineering versus all other fields? To what extent have these determinants and/or their salience changed over time for women and men? (3) To what extent is the gender gap in the selection of engineering due to (a) gender differences in attributes, versus (b) gender differences in the salience of these attributes? How has this changed over time?