Aiming to register workplace violence in health care workers, we adopted two evaluation methods: direct and indirect. The direct method is represented by the Violent Incident Form (VIF), a 16 items checklist, which resumes the key aspects of violence events, identifying spatial and temporal circumstances, aggressor, type of violence and consequences. Indirect method is constituted by the observation of injury reports, through three sources: the Prevention and Protection Service (SPP), the Public Relation Office and the Police Position of the First Aid Unit. Although the instruments adopted, thus not comparable each other, pointed out a rather high number of violence events suffered by health care workers (direct method: 34 reports in the period 2002-2006; indirect method: 25 subjects, 8.5% of total); in most cases, the events were perpetrated by a patient, and directed against female of nurses. The most reported types of violence were: kicking, beating, hitting (indirect method) and verbal assault/threats (direct method). The study pointed out that workplace violence is an important risk factor, and therefore it is necessary to consider it for preventive intervention.