One hundred and twenty five children (median age 8.71 years) suffering from perennial allergic rhinitis were treated in a randomized, double-blind, parallel group study comparing azelastine nasal spray 0.14 mg/nostril twice daily (0.56 mg/day) and placebo nasal spray. Medication was given for a period of 6 weeks which followed a 2 week placebo washout period in all patients. Subjects were aged between 5 and 12 and were skin prick positive to either house dust mites and/or cat or dog dander. Concomitant anti allergic treatment was not permitted during the study. Severity of rhinitis symptoms was scored daily by the child or his/her parents on a diary card using a visual analogue scale (VAS) for each evaluated symptom: 0, absent-100, could not be worse. Mean weekly scores were calculated. Symptoms evaluated were: sneezing, nasal blockage, nasal itch and rhinorrhea. In addition, at each clinic visit the investigator evaluated symptoms using a verbal score of 0, no symptom-3, severe. Compared to the baseline, for each of the six study weeks, the reduction in the VAS scores for all four symptoms was statistically greater for the azelastine group compared to the placebo group. The investigator's assessment at clinic visits bore out these results. Both azelastine nasal spray and placebo were well tolerated, no serious adverse events were reported. During the treatment phase of the study a total of 36 adverse events were reported by 25 patients (azelastine 10, placebo 15). The most frequently occurring events were pharyngitis (azelastine 5, placebo 3), cough (azelastine 3, placebo 1) and bronchitis (azelastine 1, placebo 3). In conclusion, azelastine has been shown to be effective in the treatment of perennial rhinitis in children aged 5-12 years and to be superior to placebo in the relief of all symptoms assessed, namely sneezing, nasal blockage, nasal itch and rhinorrhea.