Dual enrollment, also known as dual-credit enrollment or concurrent enrollment; is an innovative phenomenon that has swept through education in the last few decades closing the gap in the transition from high school to college. Dual enrollment allows high school students to be dually enrolled in courses that will earn them both high school and college credits. The number of students enrolled in dual credit course programs has tripled in the past 10 years. However, there is a lack of research as to how the accumulation of dual-credit enrollment courses affects students once they arrive at a 4-year university and if there is a positive effect on first-year persistence. Therefore, the purpose of this study is to examine the effect of dual-credit enrollment on the Grade Point Average of university students by studying those who had a prior accumulation of 12 or more dual-credit enrollment hours versus those without any dual-credit enrollment hours at a large, Texas 4-year university. The study examined GPA in the first-year (contiguous Fall and Spring semester) using inferential statistics with 225 randomly selected students who arrived with 12 or more dual credit hours in school year 2008 2009, 331 in 2009 2010, and lastly 475 in 2010 2011. The same numbers of randomly selected students without any dual credit hours were selected for each of the school years, in the academic years of 2008 2009, 2009 2010, and 2010 2011. This study was conducted using a Mann Whitney U test to determine if differences exist between two groups on one dependent variable with a 0.05 significance level. Calculations were made via the Statistical Package for the Social Sciences (SPSS). [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]