Background: Problematic gaming (PG) has become an increasing mental health issue among adolescents during the preceding years. The role of parents and the family environment in the development of PG has been repeatedly emphasized. However, the structured involvement of parents in the therapy is still largely insufficient. Resource-strengthening training for parents of adolescents with PG (Res@t-P) is a new parent-centered 8-week group intervention to fill this substantial gap. The present pilot study aimed to collect first information on its potential effectiveness in improving parental and family factors. Methods: The study was conducted in a clinical setting with N = 43 parents of adolescents with PG, applying a pre- and post-follow-up design. Standardized questionnaires on psychological stress perception, family communication, family functioning, media rules, and adolescent PG symptoms were applied at three measurement points (before, at the end of, and 6 weeks after the training). Conditional growth models were estimated. Results: Over time, an improvement in parental and family aspects as well as a reduction in adolescent PG symptoms could be observed. Conclusions: The results of the present pilot study on the effectiveness of Res@t-P are promising. No causal inferences can be drawn at this stage. A randomized-controlled intervention study is highly warranted.