Objective: We aimed to investigate the relationship between childhood trauma, dissociative experiences, and internet gaming disorder in male university students with probable attention-deficit hyperactivity disorder determined by both childhood and current attention-deficit hyperactivity disorder symptoms. Materials and Methods: Volunteers were 376 university students who completed a test battery that included a sociodemographic form as well as the Adult ADHD Severity Rating Scale, Wender Utah Rating Scale, Childhood Trauma Questionnaire, Dissociative Experiences Scale, Somatoform Dissociation Questionnaire, and Internet Gaming Disorder Scale—Short Form. Volunteers were divided into 2 groups as with and without probable attention-deficit hyperactivity disorder D based on both childhood and current attention-deficit hyperactivity disorder symptoms. Results: Childhood Trauma Questionnaire (t = −3.94; P <.01), Dissociative Experiences Scale (t = −5.97; P <.01), Somatoform Dissociation Questionnaire (t = −3.80; P <.01), and Internet Gaming Disorder Scale—Short Form (t = −5.21; P <.01) scores were significantly higher in the group with probable attention-deficit hyperactivity disorder than in those without. Two different hierarchical regression analysis models in which internet gaming disorder scores were dependent variables showed that dissociative experiences in first model (β = 0.15, t = 2.28, P =.023) and dissociative absorption in second model (β = 0.22, t = 2.76, P =.006) were associated with internet gaming disorder after controlling for childhood trauma and attention-deficit hyperactivity disorder symptoms. Conclusion: Dissociative absorption may contribute to internet gaming disorder independent of childhood trauma and attention-deficit hyperactivity disorder symptoms, however further studies are needed to investigate this claim.