Women almost always comprise a minority in engineering programs and a smaller percentage of women pursue engineering than other science and technology majors. The culture of engineering departments and negative stereotypes of women's engineering and mathematical ability have been identified as factors that inhibit women's entry into engineering and cause them to leave the major. Even for women who stay, stereotype threat or the anxiety of confirming a negative stereotype can decrease academic performance. To more fully understand this dynamic, we examined four factors associated with stereotype threat (engineering identification, gender identification, gender stereotype endorsement, and engineering ability perceptions) to determine how they impacted women's achievement and persistence in engineering at the end of their first year of an engineering program. Participants included 363 first-year general engineering students from a large public university. Students completed a questionnaire near the end of their first year. Results indicated that there were differences between men and women for gender stereotype endorsement and engineering ability perceptions, with men more likely to hold negative stereotypes of women's engineering abilities and women more likely to report higher perceptions of their engineering abilities. Engineering identification was a significant predictor of persistence in engineering, and engineering ability perceptions were significant predictors of achievement; the relationships were stronger for women than men. The fact that neither gender identification nor gender stereotype endorsement were related to achievement or persistence in engineering indicated that they were less important factors for first-year women engineering students than engineering identification and engineering ability perceptions.