The invention concerns peptide fragments 13-39 and 65-97 of the HARP factor, which inhibit angiogenesis. Advantageously, said peptides can be associated with the peptide 111-136 of HARP. The invention also concerns pharmaceutical compositions comprising said peptides or nucleic acids encoding said peptides, and their use for treating pathologies associated with an angiogenesis, in particular proliferative disorders such as cancer.