This two-group prospective study evaluated the effect of anti-reflux surgery (fundoplication) on 24 patients with severe gastro-oesophageal reflux disease (GORD) and concomitant asthma (n=13) or chronic cough (n=11). Twenty-four hour oesophageal pH monitoring and lung function tests (FEV1, FVC) were done before and within 1 year after anti-reflux surgery. A diary was kept by the patient during the 4-week period prior to surgery and during 4-week periods 6 and 12 months postoperatively, with daily monitoring of peak expiratory flow rate, respiratory and reflux symptoms and medication. In non-asthmatic patients, coughing was reduced by 47% and 80% during the day and night, respectively, 12 months after surgery (P < 0.01). Concomitant hoarseness and expectoration were also significantly reduced (P<0.05). No effect on lung function was seen. In patients with asthma, small, non-significant reductions in asthma symptom scores and consumption of rescue medication were seen. Twenty-two patients were completely free from their GORD symptoms after surgery. In conclusion, anti-reflux surgery in patients with GORD had a more favourable effect on concomitant cough than concomitant asthma.