The aim of this study was to determine whether tachykinin receptors might be involved in the mediation of the atropine- and capsaicin-sensitive third phase of a triphasic contractile response to vagal nerve stimulation of the guinea-pig isolated oesophagus. The third phase was inhibited 23.3 ± 1.7% (P< 0.001, n = 5) and 30.8 ± 9.0% (P< 0.05, n = 5) by the NK 3 receptor antagonist, SR 142 801 (0.1 and 1 μM respectively). SR 142 801 (0.1 and 1 μM) had no significant effect on the response to a submaximal concentration of acetylcholine (0.1 mM, n = 4). The third phase was not significantly affected by NK 1 or NK 2 receptor antagonists. Thus, in the guinea-pig oesophagus, it appears that while NK 1 and NK 2 receptors are not involved, NK 3 receptors play a minor role in mediating a contractile response when afferent neurones are excited by vagal nerve stimulation.