The cat has been used in the labortary as an experimental animal model in order to answer several scientific questions related to neuroanatomy, neurophysiology, neuropharmacology and behaviour. However, until 1983 the distribution of neuropeptides in the cat central nervous system had not been studied in depth. In the last eighteen years, knowledge of such distribution has increased notably. Thus, our aim here is to review currently available morphological and physiological data on the neuropeptides in the cat brainstem. We shall thus discuss the following aspects:  1) The distribution of the neuropeptides in the cat brainstem; 2) The anatomical relation among  the different neuropeptides in the cat brainstem; 3) The coexistence of neuropeptides in the cat brainstem; 4)The peptidergic pathways in the cat brainstem; 5) Comparison of the distribution of neuropeptides in the mammalian brainstem and 6) The physilogical functions of the neuropeptides in the cat brainstem.