The Internet is a useful and accessible source for health-related information for modern healthcare consumers. Individuals with adequate eHealth literacy have an incentive to use the Internet to access health-related information, and they consider themselves capable of using Web-based knowledge for health. This cross-sectional study aimed to describe the relationship between eHealth literacy and health behaviors. A total of 230 adults aged 18 to 39 years and residing in South Korea participated in the study. The mean (SD) score for eHealth literacy was 25.52 (4.35) of a total possible score of 40. The main source of health information was the Internet. Using hierarchical linear regression, the results showed that eHealth literacy was the strongest predictor of health behaviors after adjusting for general characteristics. These findings indicate that eHealth literacy can be an important factor in promoting individual health behaviors. Further research on eHealth literacy and actual health behaviors including intention and self-reported health behaviors are required to explain the impact of eHealth literacy on overall health status.