OBJECTIVE According to recent studies, valproate shows some protection against oxidative stress (OS) induced by neurotoxins. Current investigation tried to determine the possible ameliorating effects of sodium valproate (SV) against aluminum (Al)-induced cell death, apoptosis, mitochondrial membrane potential (MMP), and OS in PC12 cells. METHODS In this in vitro study, PC12 cells were treated with different concentrations of aluminum maltolate (Almal) with and without SV (50-400 µM). Cell viability was assessed by MTT assay. To measure quantitatively the effects of SV on Al-induced apoptosis and reactive oxygen species (ROS), flowcytometry using 7AAD/annexin-V and 2', 7'-dichlorofluorescein diacetate staining were employed, respectively. MMP was monitored using the retention of rhodamine 123. Catalase (CAT) activity was assayed by the rate of decomposition of hydrogen peroxide. RESULTS Exposure of PC12 cells for 48 hr to Almal (125-2000 µM) significantly reduced cell viability (IC50=1090 μM), increased ROS generation and apoptosis, and reduced MMP and CAT activity. SV reduced the Almal-induced cell death and apoptosis. Furthermore, the effects of Almal on ROS generation, catalase activity, and MMP reduction were significantly diminished by SV. CONCLUSIONS Data from this study suggest that SV can inhibit Al-induced cell death and apoptosis of PC12 cells via ameliorating OS.