The frequency of different kinds of oesophageal dysfunction (OD) namely hiatal hernia at manometry, dysmotility, hypotension of the lower oesophageal sphincter (LES) and positive acid perfusion test was investigated in 97 patients with bronchial asthma seen at a hospital clinic. Thirty-six patients had signs of hiatal hernia, 37 of dysmotility, 26 of LES hypotension and 23 had a positive acid perfusion test. Four per cent of all the asthma patients fulfilled four criteria for OD and 10%, 28% and 25% fulfilled three, two and one criteria respectively. The incidence of OD was significantly higher in patients with Exogenous (95%) than in patients with endogenous asthma (58%, P less than 0.01). The history of asthma in patients with OD was of significantly longer duration (mean 16.9 years) than that of the OD itself (mean 6.5 years, P less than 0.01). Productive cough and frequent wheezing were more common in patients with OD (46%) than in patients without (19%, P less than 0.01). Spirometric lung volumes did not differ between asthmatics with OD and those without. Asthmatics with OD seem therefore to suffer more from respiratory symptoms than asthmatics without OD.