The use of Immersive Virtual Reality (IVR) for training is an idea that is around since long time; the real, unclarified doubt about its use is whether it does really increase performance with respect to traditional methods such as classroom and on-the-job training. The most critical point of traditional training methods is the difficulty to train operators about system’s deviations from nominal conditions. But even the more advanced simulation-supported training approach, commercially represented by the Operator Training Simulator (OTS), is not immune from flaws as it is affected both by the subjectivity of the assessment (making useless the operators’ benchmarking) and by the impossibility of training simultaneously the Field Operator (FOP) with the Control Room Operator (CROP), i.e. team training. The advent of the Plant Simulator (PS) enabled to overcome the inherent limitations of the training methods. But the efficacy of using Immersive Virtual Environments (IVE) was, and to some extent still is, to prove. This paper goes exactly in that direction by explaining the preliminary results of an experiment campaign performed in a PS, which demonstrates the clear benefit of using IVR for training (field) operators. The paper even highlights that, if a PS is used, the benefits are not just limited to the training but can also be extended to operations management.