Objective To determine the anti-oxidative stress effects of allicin in PC12 cell following oxygen-glucose deprivation and reperfusion (OGD/RP) injury and its related mechanisms. Methods The PC12 cells were pretreated with allicin 24 hours before exposed to sugar-free Earle’s solution and hypoxia then reperfusion injury was used as an in vitro model of OGD/RP. The OGD/RP PC12 cell survival rate was detected by MTT and apoptosis rate was determined by Hoechst 33342 staining. The PC12 cell lactate dehydrogenase (LDH) leakage rate was detected by chemical colorimetry. The superoxide dismutase (SOD), malonaldehyde(MDA) and glutathione pexoxidase(GSH-Px) content or activity in OGD/RP PC12 cell was measured by biochemical methods. The expression levels of SOD, TNF-α and catalase(CAT) protein and mRNA were detected by Western blotting and RT-PCR respectively. Results Compared with the control group, OGD/RP group could reduce the cell survival rate, SOD and GSH-Px activity, the LDH leakage rate increased, MDA content and apoptosis rate. Compared with OGD/RP model group, allicin (60, 30 mg/L) could increase OGD/RP PC12 cell survival rate, SOD and GSH-Px activity, decreased apoptosis rate, LDH leakage rate and MDA content; allicin (60 mg/L) could increase OGD/RP PC12 cell SOD, CAT mRNA and protein express levels, reduced TNF-α mRNA and protein express levels. Conclusion The Allicin have protective effects on OGD/RP injury in PC12 cell via anti-oxidative stress.