A post-marketing surveillance study (PMSS) was carried out in Poland with 313 childrei aged 3-10, predisposed to upper respiratory tract infections. The study participant received Bioaron C® syrup, containing aqueous extract of Aloë arborescens leaves, juice o Aronia melanocarpa fruit and ascorbic acid. The main object of the present study was ti investigate its tolerability and influence on the course of an acute URTI in children. Amon; the study participants 14% received Bioaron C® as a single medication and 86% of thi patients received concomitant medications. The efficacy of the treatment was measurei according to a validated symptom score. The best results were obtained for symptom related to rhinitis and bronchitis but there was no major effect seen on pain and fevei Within the subscores rhinitis and bronchitis Bioaron C alone was able to lead to ai improvement and could contribute to a reduction in particular of the single symptom blocked and runny nose, cough and hoarseness. Treatment with Bioaron C resulted in a sig nificant improvement of the symptomology of URTI. Bioaron C was tolerated very well.