Triage: experience in a pediatric emergency service Introduction: Triage systems are a way to organize emergency services, taking the number of patients, urgency of the clinical situation and available resources into account, in order to improve access to emergency medical care and decrease waiting times. Objectives: To evaluate the results of the application of a triage system in the pediatric emergency service of the Hospital Central del Instituto de Previsión Social (HCIPS). Design and Methods: Observational, descriptive, prospective study including 1 122 children seen in July 2005, between 7AM and 4PM from Monday to Friday. Data were taken from computer records and analyzed using Microsoft Excel. A list was drawn up of diseases and signs and/or symptoms to be considered urgent due to severity or risk of death, the number of patients and their frequency at the hospital. Those requiring immediate care were categorized priority 1 (P1), and the remainder were called priority 2 (P2). Thirty minutes was designated as the cut-off point for evaluating the more severely ill patients. Results: Total number of patients designated P1: 272/1 122(24%), P2: 850/1 122 (76%). Median waiting time for P1: 10 min, p25 - p75 (5-13min) maximum waiting time was 65 min. For P2 median was 65 min p25 -p75 (20-139 min) maxmum waiting time 300 min. The proportion of patients seen within 30 minutes was P1: 79 %; P2: 36%. Patients were admitted according to priority: P1: 25/272 (9%), none of P2. Conclusion: the implementation of a triage system in the pediatric emergency service of the HCIPS showed that one quarter of patients coming to the service were considered emergencies. Presumably, and given the similarity in chief complaints, most cases were patients who had not been able to see a physician in the out patient clinic that day. Over three fourths of all emergency patients were seen within thirty minutes