Asthma is a common condition that affects approximately 10% of children and more than 5% of adults in France. Nearly 1,500 deaths attributable to asthma were recorded in 2002. The significance of asthma in terms of public health, as well as shortcomings in the management of this disease, led to the implementation in 2002 of the program for asthma prevention and management. As part of this framework, the 2004 Public Health Act sets a quantifiable goal of reducing the frequency of asthma attacks requiring hospitalization by 20% over five years. This report describes, based on data from the PMSI (Program for the Medicalization of Information Systems), hospital stays for asthma in hospitals in metropolitan France and examines trends in asthma hospitalization rates during the 1998–2002 period. Children under 15 accounted for nearly half of patients hospitalized for asthma. While hospitalizations for asthma among children were predominantly among boys, hospital stays were predominantly among women aged 15 and older. The annual hospitalization rate for asthma decreased from 10.8 per 10,000 to 8.6 per 10,000 between 1998 and 2002. However, among children under 10 years of age, asthma hospitalization rates remained stable. Among older children and adults, the decline in hospitalizations was more pronounced as patients aged. This study demonstrates the value of analyzing PMSI data to describe certain characteristics of hospital stays for asthma and to estimate trends over time. It also highlights a number of limitations, which are discussed in the report. For instance, it is not possible to assess the extent to which the observed trends are linked to changes in the management of asthma patients. (R.A.)