The safety features of a virtual reality (VR) system were studied from the physiological and psychological viewpoint within an ergonomic framework. The VR was developed for constructing a novel online hospital system using a virtual environment called “Hyper Hospital,” a medical care system constructed in a distributed manner using VR as a human interface to the electronic information network. Ten healthy young male subjects were exposed to the VR system with different intensities of physiological and psychological stimuli. As a psychological stimuli, they underwent an interview with a virtual (electronic) “nurse.” The interview session was divided into two parts, namely one of low stress and one of high stress. Following each interview session, subjects were exposed to a moving scene (similar to a roller coaster ride) of varying intensities. The responses were compared with those obtained in the control experiments in which an environmental video (just a seaside scene) was presented. None of the physiological or psychological parameters (such as urinary catecholamine release, heart rate, blood pressure, etc.) indicated that significant fatigue occurred. This implies that fatigue was not induced by the usage of our VR system when compared with the results of the control experiments.