Purpose: The purpose of this investigation was to determine the extent to which differences were present in dual credit course enrollment. Specifically examined were whether differences were present in the first semester GPA and at the end of the first two semesters for students who enrolled in dual credit courses while in high school from students who did not enroll in dual credit courses while in high school. Furthermore, the number of dual credit courses completed was analyzed, as was the extent to which the number of dual credit courses taken prior to college was related to students' first semester GPA and at the end of the first two semesters GPA. The final purpose of this study was to determine which variables (i.e., SAT English, SAT Reading, SAT Math, ACT English, ACT Reading, and ACT Math) could differentiate dual credit from non-dual credit enrollment students. For all of these analyses, the extent to which gender and ethnicity were related to dual credit enrollment was examined. Methodology: A nonexperimental, causal-comparative research design was utilized in this investigation. Participants were students who attended a large Texas community college during the 2005-2006 through the 2011-2012 academic years. Archival data regarding dual credit enrollment, gender, ethnicity, and grades were obtained from this community college. Findings: With respect to dual credit enrollment, statistically significant differences were established for almost all analyses with females enrolled more often than males and White students enrolled more often than other student groups. With respect to first semester GPAs and cumulative GPAs, dual credit enrollment students had statistically significantly higher GPAs than did non-dual credit students. Statistically significant differences were present in the number of dual credit courses completed for females and Hispanic students in one analysis and for White students in two analyses. Statistically significant differences were present in the number of dual credit courses completed with higher first semester and cumulative GPA for Black females in two analyses and for White males in one analysis. The SAT Math measure differentiated dual credit enrollment from non-dual credit enrollment. Implications for policy and recommendations for research are provided. [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.]