Introduction: Aluminum is the third most abundant element in the earth's crust .It plays a role in several neurodeGENErative conditions including Alzheimer's disease. In this study, we investigated the effects of aluminum on human embryonic astrocytes.Materials & methods: In this experimental study, we applied MTT techniques to investigate the effects of 3, 9, and 12 days exposure to aluminum on astrocyte viability. Then, we used immunocytochemical techniques to identify apoptotic GENE EXPRESSION changes induced by aluminum. We used Stata software to analyze the data.Findings: Our results showed that 3-days exposure to 1 and 1.5 mM caused a reduction in astrocytes viability, (P<0.01, P<0.03). Low levels of aluminum (500 and 100 m M) needed long-term exposure to become toxic to astrocytes, (9 days for 500 and 12 days for 100 mM) (P=0.000). Aluminum didn't show any effects on apoptotic GENE EXPRESSION.Conclusion: Long-term exposure, even to low levels of aluminum, was toxic for human embryonic astrocytes, but it seems that aluminum does not alter apoptotic GENE EXPRESSION.