Objective: Problematic internet use (PIU) is characterized by excessive or poorly controlled internet use resulting in impairment or distress. PIU is most prevalent during emerging adulthood, a period marked by an increase in psychiatric disorders, including substance use disorders (SUDs). In a sample of high-risk emerging adults, the aim of this study was to examine the relationship between PIU and quality of life (QoL), psychiatric disorders, and impulsivity. Methods: Participants were a community sample of heavy drinking emerging adults in Hamilton, Ontario (N = 709). Measures included: PIU, QoL, eight psychiatric indicators, and three domains of impulsivity. All variables that were significantly associated with PIU were subsequently examined concurrently in structural equation models. Results: PIU was negatively associated with physical QoL (β = −0.27, p