This study aimed to investigate whether antenatal taurine can reduce neuronal apoptosis in fetal rat brains with intrauterine growth restriction (IUGR) and its possible mechanisms. A total of 15 pregnant rats were randomly divided into the following three groups: control, IUGR, and IUGR+ antenatal taurine supplements. Neuronal apoptosis was detected using transferase-mediated dUTP biotin nick end-labeling (TUNEL); the expression of Bcl-2, Bax, and caspase-3 mRNA and proteins was detected by reverse transcription-polymerase chain reaction and immunohistochemistry. In IUGR groups, the results were as follows: (1) the expression of Bcl-2 decreased whereas the expression of Bax increased, accordingly, the ratio of Bcl-2/Bax decreased, (2) the expression of caspase-3 increased significantly, and (3) apoptotic neuron counts in IUGR groups was significantly increased compared with controls. In taurine supplement groups, the results were as follows: (1) the expression of Bcl-2 increased whereas the expression of Bax decreased, accordingly, the ratio of Bcl-2/Bax increased, (2) the expression of caspase-3 in fetal rat cerebral cortex tissues decreased significantly, and (3) the number of apoptotic neurons was significantly decreased compared with IUGR groups. In addition, the changes in the expression of Bcl-2, Bax, and caspase-3 mRNA and protein were correlated. So we concluded that antenatal supplementation of taurine may reduce neuronal apoptosis in IUGR fetal rats via up-regulating the ratio of Bcl-2/Bax and down-regulating the expression of caspase-3. Copyright © 2012 by Thieme Medical Publishers, Inc.