The Analyse Infections Respiratoires (AIR) II study is a prospective, multicentre survey of the management of lower respiratory tract infections in patients aged 15-65 yrs by general practitioners (GPs) in France. To obtain real-time data recording, practitioners were required to submit an anonymous copy of their drug prescriptions. They were then interviewed over the telephone about the patients' sociodemographic data, signs and symptoms, as well as their presumptive diagnosis and the investigations they had decided upon. GPs (n=3,144) reported 5,469 evaluable cases. Pneumonia accounted for 9.6% of diagnoses, acute exacerbations of chronic bronchitis 14.9% and acute bronchitis 72.5%. The symptomatology covered an extremely wide range of clinical features, which, although statistically different in terms of incidence, overlapped to a large extent across diagnoses. By contrast, hospitalization, investigations or referral to a specialist were much more prevalent in pneumonia, although still very infrequent in general terms (0.5, 1.2 and 10.8%, respectively). Antibiotics were prescribed in 96.5% of patients, with minor differences between diagnoses. However, other medications such as nonsteroid, anti-inflammatory drugs, steroids, nonspecific antitussives and bronchial liquefiers accounted for two-thirds of the prescriptions. This study demonstrates the lower respiratory tract infections encountered by general practitioners are usually mild. However, antibiotic prescription was more systematic than in previous studies and the prescription of nonspecific symptomatic treatments was twice as frequent. General practitioners did not perform additional examinations or refer on a regular basis. There was a high prescription rate for symptomatic treatment.