Internet gaming disorder is defined as excessive and compulsive use of the internet to engage in games that leads to clinically significant psychosocial impairment. We tested the hypothesis that individuals with internet gaming disorder would be less sensitive to high-risk situations and show aberrant brain activation related to risk prediction processing. Young adults with internet gaming disorder underwent functional MRI while performing a risky decision-making task. The healthy control group showed stronger activations within the dorsal attention network and the anterior insular cortex, which were not found in the internet gaming disorder group. Our findings imply that young adults with internet gaming disorder show impaired anterior insular activation during risky decision making, which might make them vulnerable when they need to adapt new behavioral strategies in high-risk situations.