Summary—Neuropeptide gamma (NPγ) induced a contractile response of the human isolated bronchus which was potentiated by the neutral endopeptidase inhibitor, phosphoramidon, but was not modified by atropine and indomethacin. NPγ was 3.31‐fold more potent than NKA. Contractile response curves to NPγ were shifted to the right and maximal responses reduced by the non‐peptide NK2‐receptor antagonist, SR 48968. The pKBof SR 48968 (8.94 ± 0.18,n= 15), calculated according to Kenakin (1987) was very close to that reported for [Nle10]‐NKA (4–10), a specific agonist of neurokinin NK2‐receptors (8.86 ± 0.13,n= 13), suggesting that the contractile effects of NPγ on the human isolated bronchus were mediated thr