When students take courses out of sequence, it can have a detrimental effect on both teaching and learning. At California State University-Fresno, we see a considerable number of freshmen taking upper division classes and an even larger number of upper-division students taking lower level classes. The purpose of this study was to examine academic preparation and performance of freshmen taking upper-division classes and the effect of inverted course-taking on students' retention and graduation. Grades earned by freshmen in upper-division courses were compared to grades of other students in the same classes. Results show that those freshmen who take and pass upper-division courses during their first year complete their degree in four years at higher rates. Those first-time freshmen who are failing the upper-division courses tend to be less prepared for college and are likely to be retained and graduate at considerably lower rates. First-year freshmen also tend to earn lower grades in those courses compared to upper-division students. (Contains 3 tables.)