Peptides are emerging as pharmaceutical agents in cancer therapy. The peptide, TLSGAFELSRDK (TLS) is a targeting ligand that can specifically triggers cellular uptake by binding to SKOV3 cells. Cell surface proteins and the C-terminal basic residues of the TLS are required for effective cell penetration, and the uptake process is energy-dependent. It inhibited the proliferation of SKOV3 cells and induced early-stage apoptosis by down-regulation of Bcl-2 expression mediated through a caspase-dependent pathway. The synergistic anti-proliferative effects of the peptide TLS and doxorubicin on SKOV3 cells were further investigated. Taken together, TLS, acting as a combination of a targeted ligand and a therapeutic agent, was a promising candidate for the development of peptide-based therapies in ovarian cancer.