The clinical efficacy of roxithromycin, administered at the daily dosage of 300 mg (150 mg every 12 hours), was evaluated in 25 patients with respiratory tract infections, mostly infectious exacerbations of chronic bronchitis. Pathogens isolated before treatment were Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus beta-haemoliticus, Haemophilus influenzae. Clinical cure or improvement was achieved in 21 out of 22 evaluable patients. The eradication rate was 91%. Tolerability was good: two patients reported gastrointestinal side effects which caused treatment discontinuation. These preliminary data suggest that roxithromycin may have a place in the treatment of respiratory infections.