Based on the descriptive analysis, a linear yearly trend, the days of the week, the period of school holidays, a seasonal effect and the unusual days (day-off) have a marked effect on the daily fluctuations of ED visits. The pattern of the daily visits during the summer periods has been modeled using a quadratic function. The day-of-week effect has been differentiated by seasonal period of the year. The final model based on the combination of variables explains 78% of the daily variations of the ED attendances and shows a good predictive performance on 2010.