Background: In an age where technology is pervasive, parents may find it difficult to educate their children in a healthy use of digital devices. Objective: In this preliminary study, we explore the potential value of an online Parent Training (PT) based on Self-Determination Theory (SDT) in fostering parents' ability to regulate their children's use of digital devices. We also investigate whether the expected improvements can be ascribed to the specific PT provided or may be linked to other forms of training. Methods: Thirty-three parents and their 29 children participated in this study. Parents attended one of two PT, based on SDT or Behavior Therapy (BT), respectively. Participants filled in a self-report questionnaire before (T1) and after (T2) the PT sessions, and at a six-month follow-up (T3). The survey investigated parental autonomy support, structure, affiliation, behavioral strategies, and children's digital device-related problem behaviors. Results: Parents and children in the SDT-PT group reported an increase in their perceptions of parental structure and affiliation at T2 and T3, and a decrease in behavioral issues at T2; parents also reported higher values of autonomy support at T2 and T3. Compared with parents attending the BT-PT, those in the SDT-PT group reported higher perceptions of autonomy support, parental structure, and parental affiliation at T3. Conclusions: Despite several methodological limitations, including a small sample and the absence of a no-intervention control group, this study offers valuable insights for planning SDT-based interventions to support digital parenting, and triggers a series of considerations regarding psychological intervention sustainability.