The term “problematic Internet use” (PIU) refers to excessive online activities and is a major social concern. Despite various sociological, psychological, and interdisciplinary studies, the risk factors related to PIU remain unclear. As psychological traits are associated with online behavior, they are often seen as potential risk factors of PIU. However, the dark personality traits (which include narcissism, Machiavellianism, and psychopathy) and their relation to problematic Internet use are only partially recognized. These traits are commonly known as the Dark Triad, and even though they have been widely researched their structure is still under discussion. This study investigates both the structure of the Dark Triad and the triad’s relation to PIU. A total of 384 participants were surveyed by online questionnaire. Our results suggest that the 3-component structure of the dark traits may be more suitable for research into online activity than a dark dyad. Moreover, the Dark Triad traits are related to high PIU levels.