Abstract The aim of the present work was to study the mechanism of action of curcumin in vasomotion of a physiologically important artery of ruminant i.e. ruminal artery. ACh and SNP were used to study the role of endothelium in relaxation of this artery. Vasorelaxatation by curcumin was studied in a dose dependent manner, on rings precontracted with 5-hydroxy tryptamine and noradrenalin, in presence and absence of L-NAME, 4AP, ODQ and 4AP+ODQ combination. SNP (1ηM–100μM) produced a significant relaxation compared to ACh (0.1–100μM) on 5-HT (10μM) and NA (10μM) induced contraction in endothelium intact rings. Curcumin (10ηM–100μM) relaxed the vascular rings in dose dependent manner with maximal relaxation up to 20.94% and 13.81% in 5-HT and NA induced contraction, respectively which was potently blocked by ODQ (10μM) and combination of 4AP and ODQ (10μM) but 4AP (10μM) and L-NAME (100μM) alone could not block the relaxation and interestingly we observed a slight increase in the tension at higher dose of the agonist (>10μM). Therefore in goat ruminal artery, curcumin at least in part, act via direct activation of sGC mediated cGMP pathway followed by opening of K+ ion channel. However other mechanisms may not be ruled out.