Aim: To estimate the values of transcranial doppler (TCD) in the determination of brain death in children. Method: Fifty-eight comatose children (from 2 days to 13 years, median 28 months) with Glasgow Coma Sores of ≤ 7 had TCD examinations. The waveforms and the cerebral blood flow velocities of the middle cerebral arteries (MCAs) were monitored at intervals. Electroencephalogram (EEG) was recorded continuously in 34 patients. Twenty children survived, 38 died, 17 patients met the criteria for determination of brain death by clinical and EEG criteria(15) or by clinical criteria alone(2). The prevalence of retrograde diastolic flow (RDF) was analysed by using chi-square test. Results: All the brain death patients displayed "special" TCD waveforms including RDF or small systolic forward flow (SFF). RDF appeared in 14, 2 and 3 patients in the brain death, non-brain death and survival group respectively. The occurrence of RDF in the brain death group was significantly higher than in the other two groups (p < 0.01). Persistence of RDF or SSF and direction of flow index < 0.8 in the MCAs for more than 2 hours in serious comatose children, was a reliable indicator to predict or confirm brain death. Using this criteria, no false negative or false positive results were found in this group of patients. Conclusion: TCD has a high sensitivity and specificity in the determination of brain death in children.