Historically, women have been underrepresented in the Science, Technology, Engineering, and Math (STEM) fields both as college majors and in the professional community. This disturbing trend, observed in many countries, is more serious and evident in American universities and is reflected in the U.S. workforce statistics. In this article, we examine historical students’ interest data in order to further the understanding of this discrepancy and to suggest methods to reverse this trend. Thirty years of historical ACT data were analyzed by expressed interest patterns, ACT scores, gender, and intended college major or career aspiration. Statistical package for the social sciences software was used to analyze the data and examine the historical trends of students’ expressed interest in STEM-related careers. Results show that there is a significant (although expected) discrepancy between the number of male and female students who expressed interest in engineering majors and careers. Significant changes have also been observed in the interest in engineering fields over time, most likely because of societal influences. These influences are most profound in computer-related fields, causing speculation that both males and females were influenced by the dot com era but that only male interest was piqued due to the rise of computer gaming in the late 1990s. Students are further grouped into three categories—well prepared (ACT ≥ 28), under prepared (27 ≤ ACT ≥ 19), and unprepared (ACT < 19). Of the total number of students who expressed interest in engineering majors, there are many who appear either completely unprepared or relatively under prepared for the demands of these fields. Data show that female students who expressed interest in STEM fields are generally in the well-prepared category; the discrepancy between those who are interested but under prepared is greater in males than females. Results from this analysis demonstrate the importance of earlier interventions to encourage students who still have enough time to get prepared for opportunities that interest them. It is also probable that students are making assumed career choices based on little or no data and may actually find their interest waning very quickly (thus making them a retention risk if they are admitted to an engineering program). This study, therefore, provides a better understanding of gender, societal influences, and ability disparities in high school students who expressed interest in engineering majors and careers. Obtained results suggested some of what needs to be done and could be used to guide future efforts in order to reverse the current trends of gender disparity and lack of female interest in engineering fields.