Due, in large part, to the significant advances in PC hardware that have been made over the last 3 years, PC-based virtual environments are approaching reality. Virtual Reality Environments for Psychoneurophysiological Assessment and Rehabilitation (VREPAR) are two European Community funded projects (Telematics for health-HC 1053/HC 1055, http:// www.psicologia.net) that are trying to develop a PC-based virtual reality system (PC-VRS) for the medical market that can be marketed at a price that is accessible to its possible endusers (hospitals, universities, and research centres) and that would have the modular, connectability, and interoperability characteristics that the existing systems lack. In particular, the projects are developing three hardware/software modules for the application of the PCVRS in psycho-neuro-physiological assessment and rehabilitation. The chosen development areas are eating disorders (bulimia, anorexia, and obesity), movement disorders (Parkinson's disease and torsion dystonia) and stroke disorders (unilateral neglect and hemiparesis). This article describes the rationale of the modules and the preliminary results obtained.