Objectives The purpose of this study is to investigate the incidence and clinical features of adverse events associated with herbal medicine, and to analyze their causality and severity. Methods This study was carried out from 159 children and adolescents who took herbal medicine in the Department of Pediatrics, ${igcirc}{igcirc}$ Korean Medical Hospital from december, 2013 to april, 2014. The data was collected by survey in person or telephone. The World Health Organization (WHO)-Uppsala Monitoring Center (UMC) criteria was used to analyze causality for each adverse events. Results 1. 207 cases were surveyed from 159 children and adolescents who took one or more kinds of herbal medicine. 2. A total of 12 general adverse events (5.8%) were reported from the study. Among these adverse events, 8 cases (3.9%) were associated with herbal medicine. 3. Gastro-intestinal system disorders were most frequently reported (70%) as adverse events, which is followed by psychiatric disorders (15%), skin and appendages disorders (10%), urinary system disorders (5%). 4. The most common clinical symptom was abdominal pain (20%), followed by diarrhea (15%), loose stools (10%), vomiting (10%) and borborygmus (10%). 5. The severity of adverse drug reactions was mostly mild (87.5%), and moderate (12.5%). There was no severe case. Conclusions The adverse events from herbal medicine on children and adolescents were mostly minor, most of them could continue herbal medicines.