OBJECTIVE: Evaluate prospectively the frequency and cause of accidents in children seen at the Pediatric Emergency Service of a University Hospital. The main aim is to subsidize the development of education and preventive programs.METHODS: Data of all children, less than 14 years old, from March 1997 to February 1998 were collected with a standard questionnaire.RESULTS: Accidents in 3,214 children were studied, 11.4% of the total. Males predominated (62.1%). Accidents were more common in the 9 to 13 year age group (33.4%), 2 to 5 year age group (27.2%) and 5 to 9 year group (25,5%). Traumatism, mainly due to falls, was the cause in 74%. Head trauma was important in the younger than 1 year, and trauma involving the extremities in the 9 to 13 age group. Bites and stings predominated in the 5 to 13 year age group, intoxication and foreign bodies in the 2 to 5 years age group. Burns predominated in the younger than 5 years. Most accidents (89.7%) were of low complexity but 20 patients had to be admitted to an ICU and 4 died in the Emergency Room.CONCLUSIONS: The child older than 9 years, male, with trauma of the extremities due to a fall was the most frequent case of accident. Prevention programs must be targeted to specific age ranges. Accidents are responsible for a great part of the overload of Emergency Services as 89.7% were of low complexity. Primary care health facilities personnel must be trained to manage accidents that do not involve complex procedures.