This study aims to determine the effectiveness of cultural intelligence at the beginning and end of the semester for undergraduate international students by comparing the instruction of humanism classes based on metacognitive, cognitive, motivational, and behavioral cultural intelligence proposed by Ang et al. (2007). Before the lecture, the metacognitive cultural intelligence score was the highest, motivational was the second highest, behavioral was next, and cognitive cultural intelligence was the lowest. Results show a significant improvement through the instruction of humanism in cognitive, behavioral, metacognitive, and motivational cultural intelligence. In conclusion, cultural intelligence can be improved through personality classes that focus on cultural intelligence for undergraduate international students. Moreover, through this study, it will be possible to provide an optimized curriculum for international university students.