A survey study (paper and pencil) among staff of elderly care institutions in 36 Danish municipalities (n = 9949) was conducted in 2005 with a response rate of 78%. The majority of the participants of the study were women (96%). The paper presents the prevalence, perpetrators, seriousness (self-rated seriousness, injuries, sick leave and type of violence) of work-related physical violence towards care workers in the Danish elderly care and the frequency of reporting the incidents to the safety organization. The findings show that every fourth caregiver was exposed to violence in 2005. Care personnel working in nursing homes and integrated institutions had the highest prevalence of violence (40%) and were also most often (10%) exposed to violence. Clients were most often (>90% of cases) the perpetrators. The most frequent types of violence were hitting (63%) and scratching/pinching (63%). Being held (32%) or kicked (27%) was also mentioned as frequent types of violence; use of weapon, throwing or hitting with a hard objects were more seldom. Nearly 1/3 of the exposed respondents rated at least one incident as very serious. There were significant associations between self-rated seriousness and type of violence, injuries and sick leave. The incidents were, in particular when perpetrators were clients, often rated as not serious. Only 22% of the victims of violence reported the violent incidents to the safety organizations. Reports of violent incidents were significantly associated with frequency of exposure, type of violence, physical injury, sick leave and perpetrators. The more frequent and most serious cases were reported most often and cases where the perpetrators were clients were reported less often than when perpetrators were others. It has been suggested that underreporting of violence occurs because it is time consuming, lacks supervisory support, because it won't make any difference, because it is part of the job, and also because there is a tendency to ‘downplay’ the violence in the elderly care. Suggestions for researches and policy makers are made.