Ethanolic extract of Aloe vera (Aloe barbadensis Miller) was examined for the cellular toxicity on HepG2 human hepatocellular carcinoma cells. Treatment with Aloe vera extract resulted in DNA fragmentation but not LDH release, suggesting an apoptosis instead of necrosis. Aloe vera induced cytotoxicity was mediated by decrease in ATP levels, whereas GSH depletion, increase in intracellular $Ca^{2+}$, or activation of caspase-3/7 could not be observed with statistical significance. No activation of caspase-3/7 suggests the possibility of caspase-independent apoptosis. Taken together, our results show that Aloe vera extract induce HepG2 apoptosis by ATP depletion-related impairment of mitochondria, which is caspase-independent.