There has been no direct functional evidence for a purinergic innervation of the human intestinal muscle. In the present study, the relaxant effects of electrical field stimulation (1 or 10Hz for 20s), ATP, and isoprenaline were studied in organ bath experiments on precontracted circular muscle strips of the human ileum. Non-adrenergic, non-cholinergic relaxations in response to electrical field stimulation in the presence of a nitric oxide synthase inhibitor were significantly reduced by the P 2 purinoceptor antagonists pyridoxal-phosphate-6-azophenyl-2′,4′-disulphonic acid (PPADS; 50μM) or suramin (100μM). A combination of the two antagonists yielded an approximately 70% inhibition at 1Hz. The relaxant effect of exogenous ATP, but not that of isoprenaline, was inhibited by PPADS+suramin. It is concluded that purinergic nerves (through P 2 purinoceptors) play a mediating role in the non-nitrergic relaxation in the human ileum.