Science career choice is partly determined by precursors such as enrollment in science and mathematics courses, which are, in turn, determined by factors such as attitudes toward science, participation in science activities, and science career preference. Participants were 1,501 students, Grades 4 through 10, from a large, national intervention study. Independent variables were gender and grade. Dependent variables measured attitude, activities, and career preference. Multivariate, univariate, and discriminant analysis and chi-square tests of association were used. Girls were less likely than boys to see science as a male activity or to believe they had not received serious attention from their science teachers. In contrast, girls were less likely than boys to see science as a fun puzzle to be solved. On three out of four measures of interest in Realistic and Investigative careers (Holland, 1997), girls showed less interest than boys. There were no gender differences for science activities and no gender-by-grade interaction effects. Results confirm the complex nature of attraction to a career in science and shed some light on differences between boys and girls in the understructure of science career interest.