Background. Paediatric emotional and behavioural disorders (EBD) are relatively common diseases. Although nonpharmacologic and pharmacologic treatments are utilized in these cases, it is sometimes difficult to manage the symptoms of EBD. Historically, Uncaria hook has been used for treating nighttime crying and convulsions in children. Recent clinical studies have demonstrated that the Kampo medicine Yokukansan (YKS), which contains Uncaria hook, is efficacious for behaviour disorders in Alzheimer's disease patients. Herein, we investigated the clinical efficacy and safety of YKS in a series of cases with paediatric EBD. Patients and Methods. We retrospectively reviewed all paediatric patients who sought Japanese Kampo therapy at our outpatient clinics between April 1, 2012, and April 30, 2013; we selected patients who were diagnosed with paediatric EBD and were treated with YKS. Results. After screening all candidates, 3 patients were eligible for this analysis. Their average age was 11.6 years (range 10-13 years). All 3 patients responded very well to YKS within 1 month. No drug-related adverse events were observed during the course of YKS treatment. Conclusion. Yokukansan may be efficacious for paediatric EBD. We believe these results warrant further evaluation of the clinical efficacy and safety of Yokukansan for paediatric EBD in a carefully designed, double-blind, randomized clinical study.