Academic dishonesty (cheating) has been prevalent on college campuses for decades, and the percentage of students reporting cheating varies by college major. This study, based on a survey of 643 undergraduate engineering majors at 11 institutions, used two parallel hierarchical multiple regression analyses to predict the frequency of cheating on exams and the frequency of cheating on homework based on eight blocks of independent variables: demographics, pre-college cheating behavior, co-curricular participation, plus five blocks organized around Ajzen's Theory of Planned Behavior (moral obligation not to cheat, attitudes about cheating, evaluation of the costs and benefits of cheating, perceived social pressures to cheat or not to cheat, and perceived effectiveness of academic dishonesty policies). The final models significantly predict 36% of the variance in "frequency of cheating on exams" and 14% of the variance in "frequency of cheating on homework". Students don't see cheating as a single construct and their decisions to cheat or not to cheat are influenced differently depending on the type of assessment. Secondary findings are that a student's conviction that cheating is wrong no matter what the circumstances is a strong deterrent to cheating across types of assessment and that a student who agrees that he/she would cheat in order to alleviate stressful situations is more likely to cheat on both exams and homework.