An apparent increase in young people dying suddenly from acute asthma has been noted in the past 2 years in Auckland. 22 fatal cases were reviewed. Prescribing habits for asthma therapy have been changing in New Zealand, with a considerable increase in the use of oral theophylline drugs, particularly sustained-release preparations, which in many patients have replaced inhaled steroids and cromoglycate. It is suggested that there may be an additive toxicity between theophylline and inhaled beta 2-agonists at high doses which produces cardiac arrest. Also when regular symptomatic treatment with bronchodilators replaces inhaled steroids or cromoglycate the patient's perception of an asthma crisis may be delayed.