The present study investigates international students'' adjustment to college in South Korea. Data were collected from 102 international college students through the College Adjustment Survey (CAS) and through qualitative interviews. The results showed the following: 1) freshmen’s adjustment level was the highest while sophomore was the lowest. This indicates that when first-year international students move up to the second year, they would struggle to adjust in college; 2) international students in the humanities and social sciences seem to have more difficulty in language/academic adjustment than those in other majors; 3) the length of stay in South Korea was a variable that had a great influence on college adjustment. In particular, the adaptation to college was low for the group whose stay was between 1 and 3 years; 4) according to the participants’ self-assessed proficiency of Korean, there were differences in academic, language, and cultural adaptation; 5) social adaptation was highly correlated with the categories of college/major satisfaction, job adaptation, and career preparation. This suggests that social support is important, especially the presence of peers from their home countries as a strong source of social support for international students.