This study was to understand associated factors with frequent exposure to Internet pornography among Korean adolescents. We used data (N = 45,783) from the 2012 Korea Youth Risk Behavior Web-based Survey to examine demographics, family environmental variables, Internet use time, mental health indicators, sexual behavior, and delinquency among Korean adolescents identified as frequent users of Internet pornography. Multiple logistic regression analysis revealed that frequent users of Internet pornography were more likely to be older males with differences in living arrangements and perceived economic status of the family. They were heavy Internet users with mental health issues, such as a higher likelihood of sadness, suicidal ideation, suicide attempts, high stress, and a lower likelihood of feeling happiness. Their higher probability of exploratory (OR =1.79-4.60), and high-risk sexual behavior (OR = 2.20-7.46), and other delinquencies (OR = 1.74-7.68) requires more attention from public health professionals.