An economic analysis was conducted comparing the cost effectiveness of fluticasone propionate with that of sodium cromoglycate (cromolyn sodium) in a group of children aged 4 to 12 years old with asthma, who required inhaled prophylactic therapy. Over an 8-week study period, 115 patients received sodium cromoglycate 20mg 4 times daily, via the spin operated dry powder inhaler, and 110 patients received fluticasone propionate 50 micrograms twice daily, via the Diskhaler (trademark held by the Glaxo Wellcome Group of Companies). Patient healthcare resource use was examined in terms of study medication, the use of rescue medication [salbutamol (albuterol) 200 micrograms] and the number of hospitalisations. The effectiveness of both treatments was examined over a range of success and failure criteria embracing peak expiratory flow rate (PEFR) improvement, symptom control and the level of adverse events related to the study medication. Results indicate that, for each UK pound spent, fluticasone propionate was associated with twice as many successfully treated patients as sodium cromoglycate, using a range of outcomes based on the goals of treatment defined in the British Thoracic Society's asthma guidelines. It is concluded that fluticasone propionate was more cost effective than sodium cromoglycate in improving PEFR and symptom control in this group of children with asthma who had a clinical requirement for prophylactic therapy.