The Swiss Sentinel Surveillance Network (SSSN) has been used as a monitoring system for asthma epidemiology. Three aspects of asthma were studied between 1989 and 2005: the seasonal pattern of asthma, practice incidence and time trends for allergic and non-allergic asthma on the basis of the association of asthma with eczema and hay fever. The purpose of this report is to use the results from 17 years of asthma monitoring to show that the SSSN can be used as an instrument of research in practice.