Although acts of threats and violence are problems that have received increased attention in recent years within Swedish pre-hospital care, only a handful of scientific studies have been carried out in this field. Threats and violence have a negative influence on the well-being of ambulance personnel. The aim in this study was both to investigate the incidents of threats and violence within the Swedish ambulance service and to describe these situations. Data was collected with questionnaires answered by 134 registered nurses and paramedics from 11 ambulance stations located in four counties. The respondents' experiences of pre-hospital care varied from 3 months to 41 years (mean=12 years, median=8 years). The results showed that 66% of the ambulance personnel experienced threats and/or violence during their work while 26% experienced threats and 16% faced physical violence during the last year. The most common kind of threat was threats of physical violence with 27% of the respondents experiencing threats involving weapons. Commonly occurring physical violence was in the form of pushes, punches, kicks and bites. In most cases, the perpetrator was the patient himself often under the influence of alcohol or drugs. The most serious situations occurred when the reason for raising the ambulance alarm was intoxication or a decreased level of consciousness.