<p>Gamification, defined as the introduction of game elements in nongame contexts, has shown potential for addressing disease prevention and health promotion through new technologies. The aim of this study was to identify and describe gamified eHealth interventions for health promotion and disease prevention in children and adolescents, the theoretical frameworks that support or endorse these interventions and the key attributes of games with evidence of their effectiveness. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for Scoping Reviews (PRISMA-ScR). The search was carried out in the PubMed, Scopus, and Science Direct databases. Related data were extracted on the basis of the research questions, and a qualitative content analysis was conducted. We retrieved 930 records, 26 of which met the eligibility criteria, and 15 studies were ultimately analysed. Most of the gamified interventions were based on the implementation of mobile health applications or video games. A high percentage of studies (80%) demonstrated the effectiveness of gamification, which improved the health-related knowledge, motivation, and attitude outcomes of the participants in the intervention group. The theoretical models underpinning the studies were reported in only 40% of the studies. The attributes of game evaluation, conflict/challenge, and rules/goals were included in all the studies analysed and were related mainly to extrinsic motivation. Despite promising results on the use of gamification in the paediatric population, more research is still needed to validate the theoretical models and consolidate the evidence. Gamification should be based on a motivational theoretical model in which the intrinsic motivation of participants is accounted for.</p>