This quantitative study aimed to determine whether participation in dual enrollment or advanced placement courses helped increase the college readiness self-efficacy of high school graduates. With the results of this study, the researcher believes that participation in dual enrollment and advanced placement courses is associated positively with high school graduates' college readiness self-efficacy. According to the results, dual enrollment participation seemed to have a more significant influence than advanced placement enrollment. The college readiness self-efficacy of high school graduates increased as the guardian's educational level increased; females, on average, had a higher college readiness self-efficacy score than males. Future research areas from the study would be to compare only juniors and seniors when discussing dual enrollment and advanced placement enrollment and distinguishing the types of dual enrollment and advanced placement courses taken by the graduates during their high school careers. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]