This study examined whether interactive Virtual Reality (VR) provides a more ecologically valid assessment of children’s aggressive social information processing (SIP) and aggressive responses than a standard vignette-based assessment. We developed a virtual classroom where children could meet and play games with virtual peers. Participants were boys (N = 184; ages 7–13) from regular education and special education for children with disruptive behavior problems. They reported on their SIP in four scenarios (i.e., two instrumental gain and two provocation scenarios) presented through both interactive VR and vignettes. Teachers reported on children’s real-life aggressive behavior and reactive and proactive motives for aggression. Results demonstrated that children found the interactive VR assessment more emotionally engaging and immersive than the vignette-based assessment. Moreover, compared to vignettes, the interactive VR assessment evoked higher levels of aggressive SIP and responses in provocation scenarios only. Results supported the enhanced predictive validity of the interactive VR assessment of children’s aggressive SIP and responses, which predicted children’s real-life aggression above and beyond the vignette-based assessment with 2 to 12% additional explained variance. Similar results were found for children’s real-life reactive and proactive motives for aggression, with 3 to 12% additional variance explained by interactive VR above and beyond vignettes. Interactive VR did not, however, evoke larger individual differences (i.e., variances) in children’s aggressive SIP and responses than vignettes. Together, these findings suggest that interactive VR provides a more ecologically valid method to assess children’s aggressive SIP and responses than hypothetical vignettes.