This study investigated the impact of Problematic Internet Use (PIU) on Iranian adolescents' Psychological Well-Being (PWB), focusing on the mediating roles of sleep quality and self-regulation. Data was collected from a sample of students (n = 228, girl = 197, boy = 31) aged 12 to 19 years. Participants completed four online questionnaires, including the PIU questionnaire, the Psychological Well-Being Scale (PWBS), the Pittsburgh Sleep Quality Index (PSQI), and the Short Self-Regulation Questionnaire (SSRQ). Results confirmed that while PIU was not directly effective on PWB, it was indirectly effective through the mediation of sleep quality and self-regulation. By gaining such understanding, we can devise interventions to enhance individuals' sleep quality and self-regulatory capacities, thereby improving their PWB.