In today’s competitive labor market, job interviews are pivotal for career development—particularly for young graduates entering the workforce. Yet, large-scale access to such training is oftentimes limited due to monetary or time constraints, and our psychological understanding of why and how training interventions are (not) effective is scarce. To bridge this gap, our preregistered research evaluates a novel Virtual Reality (VR) job-interview training designed to improve interview performance. This VR training, openly accessible for public use, immerses participants in a semi-structured, multi-modal job-interview with a virtual HR manager, thereby simulating real-world interview dynamics. To investigate the unique effects of VR, we compared the VR training experience to a conservative control condition, in which participants conducted an identical interview through a chat-based interface. A total of N = 110 participants were randomly assigned to either VR or chat training, and training effectiveness was assessed across three time waves (pre- vs. post-intervention vs. 4-months follow-up) measuring candidates’ job interview self-efficacy, perceived performance, and interview-related anxiety. Results showed that VR significantly improved self-efficacy and simultaneously reduced task-related anxiety. While the chat training showed comparable effectiveness, the VR training required only 50% of the time for comparable training benefits. In terms of underlying mechanisms, mediation analysis revealed that the VR benefits were mediated via presence and various emotional, cognitive, and physiological pathways. Finally, participants also expressed a clear preference for the VR training, recalling it more vividly, showing greater willingness to reengage and to pay more for this training. These findings underscore VR’s potential as an efficient, widely applicable, and scalable tool for job-interview training. Our study advances the understanding of VR-based interview training in organizational psychology and provides a general model and thus conceptual foundation for skill development in VR.