Despite the emerging phenomenon of sexting, scientific investigation with criminological perspectives has been limited. Utilizing data collected from 1,612 randomly selected youth in South Korea, this study begins the investigation into which criminological theory best explains sexting behaviors. Theories considered include self-control, social control, and social learning theories. Some variables of each of those theories were tested. Findings showed that peer pressure was the most important factor for two types of sexting behaviors (sexting own picture/video and sexting others’ picture/video), and that prior delinquency and positive attitude toward sexting were also significantly and positively related to both types of sexting behaviors. But social control was negatively related to only the second type of sexting behavior, and self-control was not related to both types of behaviors. As sexting has only recently begun to be studied, we recommend that future research studies examine the phenomena within the framework of social learning theory.