Adolescent gambling has reached unprecedented levels in recent years, warranting research attention due to its links with other risk behaviors and mental health issues. This study focuses on the risk and protective factors in parent-adolescent relationships affecting gambling behaviors in Swedish adolescents. We investigated the role of parenting practices, parental gambling issues, and parental attitudes toward gambling. Participants included 553 upper secondary school students who completed an online survey about gambling, parental behaviors and attitudes, and parent–child communication. The analytical sample consisted of 57.8% boys with a mean age of 16.8 years (SD = 0.9). Logistic regression models assessed the relationship between these variables, problem gambling, and gambling initiation. Despite legal restrictions against gambling under 18 in Sweden, 49% of adolescents in our sample reported gambling at some point, 25% reported gambling in the past month, and 10% endorsed problem gambling behavior. Our results indicate that parental acceptance and their own gambling behavior are significantly associated with adolescent gambling initiation, suggesting children mimic parental behaviors. Furthermore, parent–child communication and disclosure were associated with both gambling initiation and problems. Enhancing parental awareness is essential to prevent underage gambling initiation and curb future problematic gambling behaviors, given the influential role of parent–child communication, attitudes, and behaviors on adolescents’ gambling habits.