We performed a study on 25 common carotid arteries (CCA) affected by atherosclerotic plaques, comparing them to 25 normal CCA. We researched the presence and localisation of atrial natriuretic factor (ANF) and oxytocin (OX) by immunohistochemistry. We found ANF abundantly expressed in plaques, mainly localising in intima and subintima layers; by contrast normal vessels were scarcely positive or negative; finally, OX resulted negative or weakly positive in both atherosclerotic and normal vessels. Our results show for the first time ANF presence in atherosclerotic plaques of CCA and are in agreement with other studies, mainly performed in vitro, that hypothesise the involvement of this molecule in the modulation of atherosclerotic inflammatory lesions and its use as anti-inflammatory agent