The efficacy and safety of the nasally administered drug Allergodil in the treatment of allergic rhinitis were evaluated in a prospective drug monitoring programme conducted in Germany. Data from 489 children under the age 13 were included. The study was designed to gain knowledge about Allergodil in a normal clinical setting. Dosing was at the judgement of the investigator bearing in mind data sheet recommendations, i.e. one spray-puff (0.14 mg) per nostril twice daily. Patients were treated for four weeks. The occurrence of ten nasal, eye and throat symptoms was rated (0 = never, 1 = sometimes, 2 = often). All symptoms showed a statistically significant improvement at the final visit, as did the overall sums of the scores. These changes were clinically significant. Overall assessment of efficacy by the physicians and the patients was very good and good in more than 85% of patients. 70% of patients required no concomitant medication. 13.5% of patients experienced adverse events, mostly mild or moderate in severity. Safety and tolerance were assessed as very good and good in more than 97% of cases. No sedation was seen. With respect to both efficacy and safety, there were no differences between patients younger than 6 years and those aged 6-12 years. In conclusion, these results suggest that Allergodil is an effective treatment of the symptoms of allergic rhinitis in children. The subgroup of 48 young patients studied shows that Allergodil was safe and well tolerated in patients aged 2-6 years.