Purpose: This exploratory study aims to understand college students' use and perception of social media for health information by comparing college students in the USA and Korea. Method. This study surveyed 342 college students from two state-level universities in the USA and Korea (one from each country) using a convenience sample. Analysis: Independent sample t-tests were performed to observe the statistical difference between the two countries for three measures--the degree of usefulness, trustworthiness and privacy concerns--for each type of social media. The statistical differences across social media in each country were analysed using one-way analysis of variance. Results: The American students are not only more active in using social media, but they engage in more social media interaction for health care than Korean students. Also, regardless of country, students with a higher level of confidence in searching online health information and those with greater health concerns or lower perceived health status tend to regard social media as more trustworthy and more useful. Conclusions: This study identified important factors influencing social media use for health information among college students. The findings of this study suggest the potential of social media as a desired health-promotion channel for college students.