A survey of 312 adult asthmatic subjects has been undertaken. Only 3.5% of the total adult list were known to have asthma and this may represent underdiagnosis. Spirometry was normal in under half the patients and below 50% predicted in one fifth. Forced expired volume in 1s had declined more rapidly than expected with increasing age, particularly amongst smokers. Morbidity from asthma was extensive, patients reporting substantial breathlessness and restrictions of their life style; nearly half had lost time from work in the preceding twelve months. Morbidity was correlated with spirometry.