The effect of intranasal budesonide delivered from a new dry powder inhaler (Rhinocort Turbuhaler) was evaluated in a randomized, double blind, group parallel study of 83 children aged 4-16 years with seasonal allergic rhinitis. The doses 100 and 200 micrograms taken once daily in each nostril were compared with placebo. A one week run-in period was followed by a 4 weeks treatment period. Diary recordings of nasal symptoms, p.r.n. use of terfenadine tablets were made at home and rhinoscopy performed at hospital before and at the end of each treatment period. Total or substantial control of symptoms was achieved in 41% of the children in the 400 micrograms group (p < 0.05 compared with placebo), in 33% in the 200 micrograms group (p = 0.07 compared with placebo) and in 14% in the placebo group. The 400 micrograms but not the 200 micrograms group was statistically significantly better than placebo for most of the clinical effect parameters studied. The treatment was well tolerated and a battery of laboratory tests including cortisol excretion in the urine was not influenced by the various treatments. These results indicate that 400 micrograms budesonide given once daily from a Rhinocort Turbuhaler is clinically effective and safe in children with rhinitis. Further studies are needed to evaluate if this inhaler is preferable to other inhalers currently used for the treatment of rhinitis.