The authors report a case of anaphylactic shock following the injection of iodinated contrast medium for coronary angiography and complicated by two spasms affecting segments II and III of the right coronary. Vasospasm was relieved by the injection of linsidomine, revealing an angiographically healthy segment III. Such complications associated with various substances, notably iodinated contrast media, are rare. They should nevertheless always be borne in mind when evaluating anaphylactic type reactions. Vasoactive mediators (histamine, serotonin, arachidonic acid metabolites) released by the allergic reaction appear to play a major role. Treatment based upon pathogenesis can be proposed.