Various biological activities of peptides have been found. In this study, the induction of apoptosis in a human lymphoma cell line (U937) by peptide fraction separated from anchovy sauce was studied using biochemical and flow cytometric methods. After U937 was treated with a hydrophobic peptide fraction of the anchovy sauce, a sub-G1 peak, which represents apoptosis, was found in the cell cycle analysis. The apoptosis in the peptide-treated U937 cell was also confirmed by apoptotic DNA fragmentation. Furthermore, an increase of caspase-3 and -8 activities was observed. Our results suggest that the peptide fraction separated from the anchovy sauce may have cancer chemopreventive effects through the induction of apoptosis in cancer cells.