Since 1978 we have taken an interest in lower respiratory tract infections associated with Branhamella catarrhalis in Christchurch, New Zealand. In a preliminary trial, 20 patients with bronchopulmonary infection caused by beta-lactamase-producing B. catarrhalis were treated with a combination tablet of amoxycillin 500 mg and clavulanic acid 125 mg ('Augmentin') 3 times daily for 5 days. Sputum cultures were negative for B. catarrhalis within 3 days in all patients. Two of 7 patients whose sputum cultures were positive for this organism at a review 2 to 4 weeks later were successfully treated with a further course of amoxycillin/clavulanic acid.