The present invention relates to a neutralizing antibody which is capable of binding to neurotensin with high affinity. The antibody of the present invention neutralizes the activity of neurotensin, in particular the oncogenic activities of neurotensin. In particular, the present invention relates to a neutralizing antibody which binds to the human neurotensin long fragment, and having a heavy chain variable region which comprises a H-CDR1 region having at least 90% of identity with SEQ ID NO:2, a H-CDR2 region having at least 90% of identify with SEQ ID NO:3 and a H-CDR3 region having at least 90% of identity with SEQ ID NO:4; and a light chain variable region comprising a L-CDR1 region having at least 90% of identity with SEQ ID NO:6, a L-CDR2 having at least 90% of identity with SEQ ID NO:7 and a L-CDR3 region having at least 90% of identity with SEQ ID NO:8. The present invention also provides the use of such antibodies in the treatment of cancer.