OBJECTIVES: Evaluate the safety and feasibility of a prehospital system (“system”) and a support tool (“tool”) that allow the ambulance nurse to transport geriatric patients, depending on their medical needs, directly to a geriatric ward (GW), to a community emergency care centre (CECC) at a community-based hospital (CH) or to an emergency department (ED). DESIGN: Randomised controlled trial. SETTING: The Emergency Medical Services in Stockholm, Sweden. PARTICIPANTS: 806 geriatric patients who had rung the emergency telephone number 112 were randomised into an intervention group [n=410] and a control group [n=396]. INTERVENTION: The patients were randomised by the dispatcher either to an ambulance that could steer geriatric patients to alternative destinations instead of the ED, depending on the patient’s medical needs (intervention), or to an ambulance that transported all patients to the ED (control). MEASUREMENTS: The primary endpoint; number of patients steered directly to the community-based hospital [effect] i.e. the GW or CECC. The secondary endpoint; number of subsequent transfers [safety] from the CH to the ED within 24 hours after initial admittance. RESULTS: Twenty percent, 90 patients out of 449, [Confidence interval (Cl) 16.6-24.0] could be steered directly to the CH with the help of the prehospital “system” and 6.7%, 6 patients out of 90, [Cl 3.1-13.8] requested subsequent transfer from the GW or CECC to the ED. CONCLUSION: Ambulance nurses could safely and effectively steer geriatric patients to an alternative healthcare facility with the help of a prehospital decision support system and an associated decision support tool. This new system in Stockholm is a better and more effective way of using the under-dimensioned emergency care resources. It is also better for the geriatric patients. Key words: Emergency medical service; Triage; Geriatric patients.