Objective: The nine diagnostic criteria for Internet Gaming Disorder (IGD) proposed in Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) have been widely adopted, but have also faced significant criticism. This study evaluated the psychometric properties of the nine DSM-5 criteria for IGD using item response theory (IRT). Methods: Four DSM-5-based scales, including the Game Addiction Scale, the Internet Gaming Disorder Scale Short-Form, the Ten- Item Internet Gaming Disorder Test, and the Internet Gaming Disorder Scale, were administered to 1,530 Chinese adolescents and young adults. IRT models were used to assess the psychometric properties of these criteria. The potential for differential item functioning (DIF) related to sex and between adolescents and adults was also evaluated. Results: All nine DSM-5 criteria demonstrated very high to perfect discrimination (a >1.38), providing substantial diagnostic information (item information >0.476) for diagnosing IGD. These scales, despite variations in wording and scoring methods, exhibited strong correlations in total scores (r≥0.502, p<0.001) and high consistency (Kendall’s W ≥0.656, p<0.05) concerning the fitted IRT parameters. Among the nine criteria, escape showed the lowest cross-scale discrimination, item information, and difficulty. In contrast, withdrawal showed the highest item information and discrimination, and the second highest difficulty. Additionally, there was no evidence of DIF related to sex or age (adolescents vs. adults) across nearly all scale items. Conclusion These findings indicate that the nine DSM-5 criteria generally possess acceptable psychometric properties for diagnosing IGD. Notably, withdrawal may represent a core symptom of IGD. Conversely, escape demonstrated inferior performance compared to the other eight criteria, indicating a potential need for further revision.