OBJECTIVE to determine the effect of alternative regimens of nasal steroid administration on symptoms and quality of life. METHODS randomized, double-blind, parallel-group comparison. METHODS sixty ragweed-sensitive adults recruited from participants of previous studies and through media advertising. METHODS 200 micrograms of aqueous beclomethasone diproprionate nasal spray, twice daily, from 1 week before until 1 week after the ragweed-pollen season (regular) or 100 micrograms of the spray, taken as required, up to 400 micrograms daily; troublesome nasal symptoms were treated, in both groups, by increasing the daily dose to 800 micrograms until symptoms were controlled. If this treatment was insufficient, 120 mg of terfenadine, daily, was added. RESULTS One subject in the "as required"-treated group withdrew with uncontrolled nasal symptoms. In the remaining subjects, sneezing, stuffy nose, and rhinorrhea, measured by a daily diary, were significantly better controlled in the regular-treated group (p less than 0.025). Impairment of quality of life, including sleep disturbance, nonhay fever symptoms, practical problems, and uncomfortable emotions were greater in the as required-treated group (p less than 0.001). Subjects in the regular-treated group required less additional terfenadine (0.27 tablets per subject versus 1.40; p = 0.022). Eye symptoms and eye-drop use were similar in the two treated groups. CONCLUSIONS In patients with seasonal allergic rhinitis, regular use of inhaled steroids results in fewer symptoms and better quality of life than when the spray is taken only as required.