OBJECTIVES: In severely injured or acutely ill patients close monitoring of blood pressure (BP) can be crucial. At the prehospital scene and during transfer to hospital, the BP is usually monitored using intermittent oscillometric measurements with an upper arm cuff every 3-5 min. The BP can be monitored noninvasively and continuously using the continuous noninvasive arterial pressure (CNAP) device. In this study, we investigated the feasibility of a CNAP device in a prehospital setting. PATIENTS AND METHODS: The study was an observational convenience study. The CNAP device was applied to the patient once in the ambulance and measurements were carried out during transfer to hospital. The primary object was the number of patients in whom the CNAP device could monitor the BP continuously in a prehospital area en route to hospital. RESULTS: Fifty-nine patients were enrolled in this study. Fifty-four (92%) patients had their BP monitored continuously by the CNAP device. The main reasons for missing data were a mean BP below the detectable range, reduced pulse wave caused by constricted arteries in the fingers, or patients' excessive movements. The CNAP device provided continuous measurements after a median of 164.5 s. No complications and no adverse events were observed. CONCLUSION: Continuous measurement of the BP obtained by the CNAP device is feasible and safe in a prehospital setting under potentially difficult conditions.