Based on a sample of 944 respondents who were recruited from 20 elementary schools in South Korea, this research surveyed the factors that lead to smartphone addiction. This research examined the user characteristics and media content types that can lead to addiction. With regard to user characteristics, results showed that those who have lower self-control and those who have greater stress were more likely to be addicted to smartphones. For media content types, those who use smartphones for SNS, games, and entertainment were more likely to be addicted to smartphones, whereas those who use smartphones for study-related purposes were not. Although both SNS use and game use were positive predictors of smartphone addiction, SNS use was a stronger predictor of smartphone addiction than game use. •We examined the predictors of smartphone addiction.•Self-control was a negative predictor, whereas stress was a positive predictor.•SNS, game use, and entertainment-related use were positive predictors.•SNS use was a stronger predictor of smartphone addiction than game use.