This study investigated the impact of student’s diversity experiences and structural diversity of an institution on the multicultural attitude of college students. The sample utilized for analysis was 6,055 junior and senior students who attended a 4-year institution. The dependent variable was student’s multicultural attitude that included three dimensions: cognitive, affective, and behavioral intention. The student’s diversity experiences and the proportion of foreign students and professors were the variables of interest. The HLM method was used for the analysis. The results showed that the college student’s diversity experiences had a statistically positive effect on all dimensions of multicultural attitude. However, the structural diversity of an institution had a negative effect on the affective dimension, and had no significant effect on the cognitive and behavioral intention dimension. Based on these results, this study suggested that universities should offer more extensive programs of diversity to their students in order to enhance the multicultural attitude of undergraduate students during college. Also, this study called for a renewed approach to inbound internationalization in Korean universities.