Return visits to the emergency room have come under scrutiny with a view to identifying the reasons for these events. The aim of the study was to estimate the incidence of return visits to emergency room and to compare this with data from other countries, with a view to proposing a method of monitoring this parameter nationwide. Ours is the first Italian study to report the incidence of return visits to the ER and to analyse the factors correlated with this phenomenon. The incidence of return visits within 72 hours of the first visit proved to be 2.5%. Statistical analysis revealed a significant difference in the number of return visits between patients under 1 year of age and those older than 1 year. Our future objective is to re-analyse recent case-records on the basis of the indicators identified, with a view to assessing the quality of the service.