This study evaluated the usability of a Web-based portal application developed for the use of nursing staff with patients suffering from schizophrenia and related psychosis. The study was designed solely to gain direct inputs from the nursing staff (N = 76, n = 38) in acute inpatient wards in two Finnish psychiatric hospitals. The data were collected by questionnaire covering the functionality, content and benefits of the portal. The evaluation showed that the portal is user-friendly enabling a user to move inside the service and to find the relevant information. The content of the portal was interesting, understandable and easy to read. Some nurses were concerned about the effects of the portal on the patients' care, well-being or personal contacts between nursing staff and patients. Some nurses have difficulties in evaluating the portal because they did not actively use it in clinical practice during the testing period. Emphasis should be put on nurses' motivation and concerns regarding possible negative effects of the portal, which may influence the future implementation of eHealth applications in clinical practice.