Research on the impact of class size on student success has primarily been conducted in a K-12 context. In this paper, we look to extend this research to higher education by examining two cohorts of students in the multidisciplinary QUEST Honors Program at the University of Maryland. QUEST students, who have academic backgrounds in engineering, business, and science, take three required, cohort-based courses in addition to two elective courses with other students at the University. In 2013, the QUEST Honors Program switched from cohorts (class sizes) of approximately 65 students to cohorts of approximately 45 students. This paper examines the impact of class size on two proxies of student success, the assessment of individual-level student learning outcomes and final course grades. This longitudinal data was obtained from two cohorts of different sizes in two of the program's required courses. The comparison of learning outcomes assessment data and student grades across various class-size conditions enabled the authors to evaluate the impact of class size on two elements that could indicate student success.