To investigate the accuracy of clinical severity assessment of asthmatics and to compare emergency and subsequent ward management with British Thoracic Society (BTS) Guidelines, the records of all patients admitted for severe asthma (46) over a 5-month period to a District General Hospital were inspected. Variations from recommended management were revealed. Appropriate oxygen administration was often not provided in casually and patients frequently left hospital before their discharge criteria were attained: recommended diurnal variations in peak flow were exceeded in 26%. Eleven per cent of discharges were against medical advice, making provision of adequate management logistically difficult. Adherence to BTS guidelines on the need for arterial blood gas (ABG) analysis would have led to a failure to detect significant hypoxaemia in 25% of cases. This study identified substantial variations from BTS management guidelines. It is suggested that oximetry is necessary on arrival to guide selection for arterial blood gas analysis.