The advent of the Internet has made pornography more accessible to many people, including teenagers. This systematic review aimed to synthesize data on factors associated with the consumption of sexually explicit internet materials (SEIM) among adolescents. A total of 753 records in Scopus, Embase, MEDLINE/PubMed, and PsycINFO databases were sorted. Forty-eight quantitative survey studies that presented original empirical results and addressed SEIM use among adolescents were included for data extraction, quality analysis, and synthesis. The prevalence of SEIM use varied substantially between studies due to inconsistencies between the operationalization methods used to assess the theoretical construct of SEIM, the period of use (days, months, years), and the age of the participants. SEIM use was highly related to being a boy and having an independent relational style. It was moderately associated with more sexual agency and hyperfemininity for girls and associated with small-to-moderate effect size, with more willingness to engage in casual sex. Sexual performance orientation, sexual permissiveness, bullying behavior, and Internet addiction might be associated with SEIM consumption, although the effect size of these associations was not calculated. Among developmental predictors with high and medium effect sizes, greater use of SEIM in adolescents was associated with being older or reaching puberty. Peer pressure or striving for peer popularity can account for boys' greater exposure to SEIM. The results described show the importance of standardizing the evaluation of SEIM use. Literacy in the use of pornography among teenagers is essential to prevent the possible negative impacts of SEIM consumption.