The accessibility and availability of a variety of online gambling for adolescents is a public concern. In the current literature, it remains unclear in which activities the greatest prevalence occurs. Moreover, it is well-known that different types of gambling activities carry different levels of risk just as have distinct socioeconomic, and mental health-related consequences. The main aim of this study is to systematically review the current literature in order to explore the prevalence of different types of online gambling activities reported by adolescents and their relationship with other reported variables when available. It will be conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses-P 2015 statement for systematic review and metaanalysis protocols. An electronic literature search will be conducted using the following databases: PubMed, PsychINFO, ScienceDirect, Web of Science, and Google Scholar using search keywords and logic as follows: “(Internet OR online) gambling AND (adolescents OR young people)”. Additionally, further articles will be identified through searching the citations in the literature selected. The overall percentage of online gamblers and the percentage of online gamblers for each type of gambling activity were identified or calculated. Seven-teen articles met the eligibility criteria. The included studies comprised 15 crosssectional and two longitudinal designs. Most of the research was conducted in Europe. The online gambling modalities detected were sports bets, card games, gambling machines, casino games lottery games, scratch tickets, bingo, gambling in social networking, stock market investment, and mahjong. Only two studies provided associations between a specific online gambling activity and socioeconomic and mental health associations, founding involvement in online sports betting and in online casino game is a risk factor to the development of disordered gambling. A consensus on the evaluation method of the problem and updated questionnaires collecting information regarding the new online betting modalities are critical.