Thalidomide has been shown to have therapeutic potential in a number of conditions including cancer. The aim of this study was to evaluate the apoptotic effects of thalidomide on a pancreatic cancer cell line. Treatment with thalidomide decreased the viability of BxPc-3 cells in dose dependent manner. Using flow cytometry analysis, determination of whether thalidomide treatment of BxPc-3 cells at concentrations of 10, 25, and 50 μg/ml affected the number of annexin V-positive cells was evaluated. The percent of apoptotic cells were 9.5±2.6%, 21.7±3.6% and 29.3±4.7% respectively in the BxPc-3 cells at 10 μg/ml, 25 μ/ml and 50 μg/ml of thalidomide treated for 24 hours. Thalidomide induced the expression of pro-apoptotic Bax in the BxPc-3 cells and increased the Bax: Bcl-2 ratio. In addition, the results of this study showed that thalidomide increased apoptosis induced by gemcitabine. (Cancer Prev Res 15, 39-44, 2010)