This study aimed at measuring the medico-economic interest of a care management programme established for asthmatic patients in the Amiens region ("Action Asthma Amieris") by using and comparing different evaluation tools. Three tools were used in parallel: 1) a questionnaire for collecting information on healthcare received was completed monthly by 305 patients recruited by 73 physicians between November 1998 and January 1999; 2) data issued by the national insurance fund for the years 1998 and 1999, for those patients included after January 1999; and 3) data on all hospitalisations for 1998 and 1999 in the University Hospital Centre obtained from the French hospital information database (PMSI). Data from the national insurance fund and from the PMSI are essential to evaluate costs, since the patients' statements proved to under-estimate the amount of healthcare administered and received. Following the implementation of this asthma care management programme, an increase of pharmaceutical expenses and a decrease in the number of hospitalisations for asthmatic patients were observed.