This study examines the criminal responsibility of children involved as narcotics sellers through an analysis of the Medan District Court decision. The research focuses on three main issues: the determination of criminal responsibility for children in narcotics offenses, the implementation of the Juvenile Criminal Justice System (SPPA) in handling such cases, and the considerations applied by judges in issuing decisions against children as narcotics sellers. This study employs a normative juridical research method using a statute approach and a case approach. The legal materials consist of primary, secondary, and tertiary legal materials collected through literature research and analyzed qualitatively through juridical interpretation. The results indicate that criminal responsibility for children involved in narcotics selling cannot be equated with adult offenders because it must consider the child's capacity for responsibility, element of fault, degree of involvement, and possible mitigating circumstances. Although the Narcotics Law provides strict sanctions against illicit distribution, its application to children must be harmonized with the principles of the SPPA Law, which emphasizes protection, rehabilitation, diversion, restorative justice, and the best interests of the child. The implementation of the juvenile criminal justice system in narcotics cases involves special procedures during investigation, prosecution, and trial; however, its effectiveness remains challenged by the strong punitive orientation toward narcotics offenses and limitations in applying diversion mechanisms. Furthermore, the analysis of the Medan District Court decision shows that judges consider juridical, sociological, and philosophical aspects in determining accountability. The decision reflects an effort to balance legal certainty, justice, and child protection, although consistency in applying restorative principles remains necessary.