To remedy problematic Internet use (PIU) and problematic online gaming (POG) in adolescents, much is expected from efforts by parents to help youths to contain their screen use. Such parental mediation can include (a) refraining from acting, (b) co-viewing or co-gaming with the teen, (c) active mediation, and (d) restrictive mediation. We evaluated if parental mediation practices are linked to PIU and POG in adolescents. No type of parental mediation was consistently associated with lower or elevated problematic screen use rates in the adolescents. Refraining from parental mediation tended to aggravate screen use problems, whereas active mediation (talking to the teen) may mitigate such problems in PIU, but less clearly in POG. The link of restrictive mediation with problematic screen use varied from positive to negative, possibly depending on type of restriction. In both PIU and POG, family cohesion was related to lower rates of the problem behavior concerned and family conflict to higher rates. D