LfcinB9 is a peptide derived from lactoferricin B. In the present study, the effect and relative mechanism of LfcinB9 on human ovarian cancer cell line (SK-OV-3) in vitro and in vivo was investigated. The data obtained indicated that LfcinB9 exhibited low hemolysis activity and significantly inhibited the proliferation of SK-OV-3 cells in vitro. In addition, the apoptosis of SK-OV-3 cells was induced through up-regulating the production of reactive oxygen species and activating caspase-3, caspase-9 on both transcription and translation level. Finally, LfcinB9 significantly prevented the tumor growth in the SK-OV-3-bearing mice model. These results indicated that LfcinB9 could be a potential agent for the treatment of ovarian cancer. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.