Akt mediates survival signals which preserve various cancer cells from apoptosis. Its correlation with chemoresistance of cancer cells has attracted much attention. But how Akt affects vincristine-induced cell death in retinoblastoma is unknown. Here we show that Akt activity is involved in vincristine-induced cytotoxicity in retinoblastoma SO-Rb50 cells. Inhibition of Akt can decrease the survival of both sensitive and vincristine-resistant SO-Rb50 cells and increase the sensitivity of both cell lines to vincristine by enhancing the cell apoptosis and increasing the cellular accumulation of the drug. Akt may be a target for reducing drug resistance that improves the treatment for retinoblastoma.