Bovine lactoferricin (Lfcin B) is a heparan sulphate-binding peptide derived from bovine milk protein lactoferrin by acid-pepsin hydrolysis. It is known for its antimicrobial and anti-cancer properties. Being a natural product makes it attractive to be exploited for cancer therapy without the fear of side effects. Lfcin B has been known to selectively induce apoptosis and impart anti-angiogenic properties in several human cancer lines, thereby making them refractive to the effects of angiogenic growth factors. In this study, the objectives were to evaluate the effects of Lfcin B on the cellular functions of MDA-MB-231 breast cancer cell line in vitro and to evaluate the effect of Lfcin B in a mouse model of breast cancer using in vivo imaging system (IVIS). Study of in vitro effects of Lfcin B against the MDA-MB-231 showed that it was capable of inducing apoptosis and inhibit migration of the cells. It was able to inhibit in vivo tumour growth in mice when delivered through intratumoural injections proving that Lfcin B is a potential anticancer agent to be exploited as a therapeutic agent.